“She burns green! Rosie, by God, we’re rich.” Those were the words by which Aaron Winters supposedly announced his discovery of borax in Death Valley. At the time, the United States was importing about 400,000 pounds a year, and the borax retailed at a price of fifty cents a pound. Borax was nicknamed the “White Gold of the Desert.”

Uses of Boron Compounds

Laura Runkle, in “Mente et Malleo: Practical Mineralogy and Minerals Exploration in 1632” (Grantville Gazette 2), lists boron as one of the many materials needed for “chemical manufacturing.” In particular, it’s an essential ingredient in the manufacture of heat- and shock-resistant borosilicate glass. This, in turn, is an “infrastructure” item for the USE’s chemical laboratories and small-scale chemical production facilities.

Borax was probably first used by goldsmiths and silversmiths. It could be used as a flux to reduce the melting point of various metal ores, converting them into a slag from which the precious metals could be separated (Austin, The fire assay of gold, silver and lead in ores and metallurgical products 40). Borax may also be used as an aid to the hard soldering of metals, as a borax coating prevents oxidation of the metal surfaces being joined.

Borax was also used, at least by the sixteenth century, for refining. After an air blast, the “viler metals” would “slag off” as oxides, whereas the noble metal would remain molten. (Rose 381ff). It has been shown that small-scale miners can concentrate gold from its ore using borax and charcoal, rather than mercury or cyanide. (GEUS)

Metals could also be assayed, pre-RoF; you would test the material using fluxes with various strengths of borax.

The first European to suggest the addition of borax to glass was Johann Kunckel (1679); the glass in question was used to make imitation precious stones (hopefully with the buyer’s knowledge).

Borax was also used in pottery glazes (by 1699, possibly much earlier) and as an enamel flux (1758).

The “borax bead test” was developed in the mid-eighteenth century. It depends on the ability of fused borax (borax heated to remove the water) to dissolve metal oxides and, in the process, form complex borates with colors which are characteristic of the metal in question.

There was some medieval experimentation with borax (and boric acid) as a medicinal agent, but their only real medical value is as a mild antiseptic (Lister in 1875). However, they do have some additional, indirect, health benefits. Prior to the development of refrigeration, boric acid was used as a food preservative (1887).

Boric acid and many of its salts are also fairly benign pesticides. Boric acid can be used to inhibit bacterial contamination of penicillin cultures (Mackey, “Crude Penicillin,” Grantville Gazette 10). Zinc borate may come in handy to make sure that our aircraft don’t fall apart because of fungal attack on casein glues. Hollombe, “On the Design, Construction and Maintenance of Wooden Aircraft,” Grantville Gazette 6).

The principal modern use of borax is in the manufacture of borosilicate glass, which typically is 5–20% boron oxide. (Cooper, “In Vitro Veritas,” Grantville Gazette 5). Note that boron oxide can be used in making glass fibers, of the E (electrical, an aluminum borosilicate), C (chemical), and D (high dielectric constant) types. These may in turn be used to make glass-reinforced plastic.

Other modern uses of borate salts are as a welding flux, detergent, water-softener, household bleach, rust inhibitor, weatherproofing agent (for wood), fireproofing agent (for fabrics) and fertilizer ingredient.

The 1999 domestic consumption of boron compounds included: insulation-grade glass fibers (193,000 metric tons boron oxide content), textile-grade glass fibers (71,100), borosilicate glasses (25,900), soaps and detergents (23,200), fire retardants (15,310), enamels, frits and glazes (14,400), agriculture (14,000), metallurgy (552), nuclear applications (454), miscellaneous (22,800), and unknown (35,400). (USGS)

There are also some more exotic boron-based materials. Boron nitride and boron carbide are about as hard as diamond, and have been used as abrasives, in wear-resistant parts, and in body armor.

Boron nitride powder is an excellent insulator, and resistant to chemicals and heat. It can be hot-pressed into a variety of shapes. (McGHEST/Boron).

Boron trichloride and the other boron halides can be used as catalysts. Boron trichloride can be reacted with hydrogen gas at high temperatures, forming boron vapors, and this can be deposited as amorphous boron on tungsten wire. The boron-tungsten wires can be used to make unidirectional composites.

Elemental amorphous boron imparts a green color to pyrotechnic flares. Crystalline boron can serve as a p-type dopant in silicon semiconductors.

Ferroboron (iron-boron alloy) is used to harden steel and to deoxidize copper-base alloys.

The Pre-RoF Tincal Trade

The resources of the USE are limited. Hence, it doesn’t want to send out prospectors if it can meet its needs by simple trade.

The down-timers knew borax under the name tincal (other spellings, too), and Europe imported it from Tibet, mostly by way of India and the Ottoman Empire.

According to Mackey, “Crude Penicillin” (Grantville Gazette 10), in our time period, “borax was one of some twenty-seven common mineral substances used in medicinal or cosmetic recipes. While the most expensive mineral ingredient (2–3 guilders per pound), borax nevertheless was available throughout much of Europe.” And that was despite the fact that borax was traveling all the way from Tibet.

How much borax is immediately available to the USE? Its use in the early seventeenth century was mostly as a flux by goldsmiths, which implies that it was a low volume commodity.

The Venetians were the European “gatekeepers” from prior to 1500 until the late seventeenth century. The Persian-Ottoman wars of 1526–1555, 1577–1590, 1602–1612, 1623–1638, 1722–1727, 1730–1736, 1743–1747 and 1776–1779 disrupted the Near East segment of the long trade route, and Venetian economic power declined as a result of European competition for Mediterranean sea trade and the Ottoman takeover of Venetian overseas territories.

The reins of control were taken up by the Dutch, who presumably acquired tincal in India and then shipped it around Africa.

Both the Venetians and their Dutch successors made the most of their import monopoly. In 1750, the London price of tincal was 700 British pounds per ton (Travis 32). That made it still an extremely expensive commodity. The price dropped to 400 by 1815; this is probably attributable to reduced shipping costs.

A description of the Tibetan trade in 1840–50 said that the tincal is carried, in 30–40 pound saddlebags, by sheep, in a drove of 800–1000 animals. Each beast is supposedly bearing its own weight in tincal, although that seems rather high to me. Based on data for Asian breeds, we are probably talking about two 30–40 pound saddlebags apiece. So one drove is 48,000–80,000 pounds, or 24–40 tons. The source didn’t specify the number of droves per year.

One of the problems with the Tibetan tincal trade is that the borax passed through so many middlemen, and was such a high value item, that it often arrived in a highly adulterated form. It would contain alum, common salt or even sand. (Travis 16) Hence, one motivation for developing a European source would be to be able to exercise a greater degree of quality control.

Development of the Boron Industry in the Original Time Line

The background information given in this section is not necessarily available to the up-timers of Grantville, but is useful in appreciating how important the various known sources of boron are likely to be.

There are at least 36 boron-containing minerals. Borax (disodium tetraborate decahydrate) was the first commercially important borate. Others include tincalconite (disodium tetraborate pentahydrate), kernite (disodium tetraborate tri- or tetrahydrate), “cotton ball” ulexite (sodium calcium pentaborate octahydrate), colemanite (calcium triborate monohydrate), priceite (dicalcium pentaborate monohydrate), boracite (magnesium borate chloride), and sassolite (crystalline boric acid). Borates are salts of boric acid, and the acid is found in solution in some brines and hot springs. Sodium borates (borax, tincalonite, kernite) are water-soluble and therefore easier and cheaper to process than calcium borates. (Scott 90).

The first alternative to Tibetan tincal was the boric acid of Tuscany, discovered in 1777 by Francisco Hoefer, a German chemist in the employ of the Grand Duke of Tuscany. The first successful effort to commercially develop these hot springs was by Francois de Lardarel in 1818. In its initial decade of operation, his facility produced about 75 tons of boric acid each year. By the 1850s, the Tuscan output had brought the price of borax down to less than 100 British pounds per ton; the 1860 production was about 2,000 tons (Travis 26, 32).

South America was identified as a source of boron compounds in 1787, at Potosi, Bolivia. Borate deposits were later found in Peru, Argentina and Chile. However, the South American deposits weren’t placed into commercial production until 1852 (NBRI), and production was minor until the 1880s (Travis). It is worth noting that the western deposits are on a plateau at an altitude of about 15,000 feet.

The first borate discovery in North America was in 1856, when Dr. John Veatch tested the waters from Lick Springs, in Tehama County, California. Some months later, at “Alkali Lake” (renamed “Borax Lake”), he found that the lake bottom (virtually exposed during the summer), under a few feet of “soapy matter,” had an eighteen inch thick layer of borax-bearing clay, with a borax content averaging about 100 pounds/square yard. That suggested that the whole lake could produce about 128 million pounds. The production cost was three cents/pound; borax then sold for fifty cents/pound. (Hurlbut 137). Do the math . . . .

Prospectors fanned out across California and Nevada. Searles Lake, in San Bernardino County (McGHEST) was put in production in 1873. Production was initially by excavating surface borax crusts, then (together with potash and soda) from brine wells (1916).

Rosie and Aaron Winters found borax near Furnace Creek Ranch in 1881. By 1883, the famous twenty mule teams were hauling ten ton wagon loads of borates out of Death Valley. Some twelve million pounds were carried the 165 miles to Mojave depot in 1883–1888. (Borax Museum).

Another borate mining region lies in Turkey. A calcium borate was found, quite accidentally, at Panderma in 1865. This “pandermite” was easily carved, and statues made of the material came into the hands of a French engineer and amateur chemist named Desmazures. He was astonished to discover that the statues had a high boron content. He traced the figurines back to their source, and quickly obtained a mining concession (Travis 28). Curiously, the Anglo-centric Encyclopedia Britannica 11th edition (EB11), published in 1911, said that borax was “mainly derived from the boric acid of Tuscany.”

The London price of borax was 35 pounds/ton in 1880, but rose to 60 in 1884. This was probably attributable to its use in enamels and glazes. But thanks to the Californian production, the London price dropped again, to 30 (1890) and 16 (1900). The latter was equivalent to 3.5 cents/pound. (Travis 35). USGS gives a 1900 U.S. price of $111/ton ($2170 in 1998 dollars.)

Some notion of the relative productivity of these different sources of borates (and boric acid) can be gleaned from statistics. In 1895–1905, the average annual production of borates was as follows:

United States 25,000 metric tons

Chile 10,000

Turkey 9,000

Peru 5,000

Italy 2,700

Tibet few hundred

(Travis 35)

Bear in mind that the Tibetan and Italian producing areas had been exploited for a longer period than those of the Americas or Turkey, and so these figures may underestimate the ability of those areas to supply the USE in 163x.

Corning introduced heat-resistant and virtually unbreakable borosilicate glass ovenware in the 1920s, but sales were poor. Walter Thompson told Corning in 1929 that the price of Pyrex® ovenware was simply too high; ninety cents for a Pyrex® pie plate, versus fifteen to forty cents for a metal one. (Stage 169). Curiously, the 1919 price premium for small borosilicate glass laboratory beakers was smaller; a 250cc Griffin low form was 23 cents borosilicate, 19 cents ordinary glass. (Daigger 40).

In 1925, kernite was discovered, in Kern County, California, and the Death Valley mining operation was shut down. The kernite deposit was then the largest known sodium borate deposit in the world (four square miles and a hundred feet thick). Unfortunately, it lay at a depth of 130–1,000 feet. It was worked for thirty years by underground methods, and subsequently, more cheaply, as an open pit. (Hurlbut 140). By 1935, the price of borate had dropped fifty percent. (Scott 90).

It was the kernite discovery that brought prices down sufficiently to make borosilicate glassware a common household item. Fiberglass was first commercially produced in 1936, and by the Late Thirties, borosilicate glass was used to make fibers. (Scott).

In 1960, Kern was eclipsed by the discovery of the sodium borate deposit at Kirka, Turkey. (NBRI). Mining began there in the mid-seventies. (Garrett xiv). Nonetheless, the EA/Kernite article says that “Very small deposits are in Argentina and Turkey,” which makes you wonder how often they update their content.

In 2001, the leading producers of boron oxide (derived from borate) were the United States and Turkey, distantly trailed by Chile and China. Total world production of boron oxide was 1,546,000 metric tons.

Boric Acid and Borax in Canon

In Cologne, in April 1634, Gysbert discovered that borax was the solution to the penicillin culture contamination problem. (Mackey, “Prepared Mind,” Grantville Gazette 10).

In April 1634, Sharon Nichols comments, “We’re probably going to have trouble with the borax, too. The Turks seem to be the only ones who’ve got it, and they’re not being real friendly so far.” (Flint and Dennis, 1634: The Galileo Affair, Chap. 29). It’s not so much that the Turks are the only ones who can produce it, but rather that they were the only ones selling it to Europeans.

By the summer, at least, Sharon is aware of alternatives close-at-hand. A recent high school graduate with strong chemistry aptitude, Lewis Philip Bartolli, is sent to Tuscany to search around Larderello for boric acid-rich waters and then, with the aid of the Cavriani office in Florence, acquire mineral rights and set up a production process. He is sidetracked by a forgery investigation on behalf of the Grand Duke, but the forger is a member of the Inghirami family, and as part of the price for letting their prodigal son off lightly, the Inghiramis agree to supply the labor and materials for the Larderello operation. (Cooper, “Under the Tuscan Son,” Grantville Gazette 9).

Prospecting for Borates: Knowing Where to Look

Library research in Grantville will reveal the names of several localities where boron compounds may be found.

Germany. Prospecting begins at home. According to the “Boracite” article in 1911 Encyclopedia Britannica (EB11), “Small crystals bounded on all sides by sharply defined faces are found in considerable numbers embedded in gypsum and anhydrite in the salt deposits at Luneburg in Hanover.” It adds that a massive form of the mineral, Stassfurtite, “occurs as nodules in the salt deposits at Stassfurt in Prussia: that from the carnallite layer is compact, resembling fine-grained marble, and white or greenish in color, whilst that from the kainite layer is soft and earthy, and yellowish or reddish in color.”


Italy. Boric acid is found in volcanic vapors and hot springs, principally in the Lipari Islands and in Tuscany.

The Lipari Islands are dominated by the eponymous Mt. Vulcano; boric acid is said to occur in the crater in sufficient quantities to have been exploited commercially in the old time line. Unfortunately, the Lipari Islands are part of the Kingdom of Naples, which is under the control of the Spanish Hapsburgs.

The Tuscan resources are both more accessible and far greater. Although the Encyclopedia Britannica errs in asserting that, in 1911, Tuscany was still the “main source” of borax, it was the Tuscan boric acid (which could be converted into borax) which broke the Tibetan tincal monopoly.

EB11 also may mislead up-timers as to exactly where in Tuscany the boric acid is found. Almost poetically, it remarks, “the chief source of boric acid for commercial purposes is the Maremma of Tuscany, an extensive and desolate tract of country over which jets of vapor and heated gases (soffioni) and springs of boiling water spurt out from chasms and fissures. In some places the fissures open directly into the air, but in other parts of the district they are covered by small muddy lakes (lagoni).”

The term “Maremma,” properly speaking, refers to the marshy coast of Tuscany. The EB11’s article on Tuscany warns that “malaria is prevalent,” and this would surely be confirmed by Grantville’s down-time associates. George Dennis, writing in 1848, quoted a proverb, “In the Maremma, you get rich in a year, but you die in six months.”

However, the boric acid is actually found, not in the malarial lowlands, but in the Colline Metallifere (Metalliferous Hills) just south of Volterra. The up-time books do offer a few clues that this is the case. For example, the EB11 article on Italy mentions that “boracic acid is chiefly found near Volterra.”

The Colline Metallifere had been mined, since Etruscan times, for rock salt, alum, sulfur, mercury, lead, zinc, and other valuable materials.

There are some better clues as to where to look. Given the volcanic origin of boric acid, it would make sense to review articles on volcanoes in the encyclopedias. The diligent researcher would learn that “Near Lardarello in Tuscany, boric acid has been produced from scalding natural steam for more than a century.” (Encyclopedia Americana/Volcanoes). After a misleading reference to the Maremma, EB11/Volcano notes that “From Sasso in Tuscany it [boric acid] has received the name of sassolin or sassolite.” (The area of Lardarello, by the way, is thought to have inspired Dante’s Inferno.)

Most world atlases don’t show the location of either town but Lardarello is in the National Geographic Atlas of the World (1975). Moreover, considering the percentage of Grantville’s population which is Italian-American, there is a pretty good chance that, if you go door-to-door, you can find detailed road maps and guides to Italy and even, specifically, to Tuscany.

Lardarello, for example, is mentioned in The Green Guide: Italy (p. 467), as being 21 miles south of Volterra, in the heart of the Colline Metallifere, and featuring “volcanic steam jets.” Jonathan Keates’ picture book of Tuscany not only identifies Lardarello as the place where Francois de Lardarel harnessed geothermal energy to facilitate boric acid extraction (p. 93), but also shows where Lardarello is situated relative to the more familiar towns of Volterra and Massa Marittima. That’s fortunate.

The town of Lardarello was founded in the 1840s, so you won’t find it on any down-time map. However, the Bagno a Morbo near Lardarello may correspond to the Aqua Volaternas, a hot spring shown on a third century Roman cartogram, the Tabula Peutingeriana (roughly the classical equivalent of a AAA “TripTik”). The spa was used medicinally by Lorenzo the Magnificent.

From up-time sources unavailable in Grantville, I can state that the soffioni area includes, not only Lardarello and Sasso Pisano, but also the villages of Pomarance, Monterotondo, Montecerboli, and Castelnuovo Val di Cecina.


Turkey. It is actually rather ironic that, for hundreds of years, the merchants of the Ottoman Empire acted just as middlemen in the tincal trade, even though Turkey is rich in borates. By 1911, the Turkish borate ore Pandermite was shipped out of the port of Panderma (Greek Panormus), on the south shore of the sea of Marmara. The up-timers don’t know whether this was a mere transshipment point (like Leghorn/Livorno in Tuscany) or the actual source of the ore. They also may have difficulty figuring out where it is located. The port does appear in my Hammond Citation World Atlas (HCWA), but under its ethnicized name of Bandirma. If you look up “Panorma” in the modern Encyclopedia Britannica, you will discover the name change.

Modern geologists know that the main borate deposits of Turkey are in western Anatolia, at Sultancayir, Ermet, Bigadic, Kestelek and Kirka. The Bigadic formation is under 25 to 410 meters of sediment (Lyday), and it’s the shallowest of the five (Helvaci Fig. 1).


The Americas. Even if the Spanish were our allies, the cost of collecting and transporting the borates of the American West would be a formidable objection to exploiting those admittedly massive deposits. The one advantage that the American West has over the European sites is that the locality information which we possess is much more precise. By studying the Encyclopedia Americana, the 1911 Encyclopedia Britannica, and other encyclopedias, and any available rockhounding guides, one can compile the following California locations:

Death Valley, in Inyo County (the Audubon Society guide mentions Mount Blanco)

Borax Lake, near Clear Lake in Lake County, California

Borax Lake, in San Bernardino County, California

near Daggett, in San Bernardino County

Los Angeles County

Searles Lake, in San Bernardino County

Kern County (the Audubon Society guide mentions the town of Boron and EB11/Borax says that since 1927 this was the principal world source of borax.)

Hopefully these will appear in an up-timer’s Road Atlas, and don’t forget that Mike lived in California. HCWA identifies four borax (“Bx”) locales in the state.

Insofar as South America is concerned, the major deposit is in the Atacama desert(EB11/Borax) of northern Chile. These dried lake deposits are also important as a source of nitrates for fertilizer. There is also borax in Argentina and Bolivia.


Tibet. While Tibet at least isn’t controlled by outright foes of the USE, the borax is in remote, mountainous regions. And although the 1911 Encyclopedia directs us to the lakes of “Pugha,” “Rudok,” and “Tengri Nor,” the place-names have changed since the Chinese takeover, and so a late twentieth century map isn’t very helpful.


In most cases, the encyclopedias only guide us to within several miles of the actual deposit. To actually pinpoint it, we need to get out in the field and start looking. So, just what are we looking for? We don’t want to heft every rock in an area of a hundred square miles and peer at it. We can narrow down our field of search by understanding the geology underlying the formation of boric acid and its salts.

Boric acid is found in the waters and vapors of geothermally active regions. Where, then, should we look for boric acid? Wherever there are indications of geothermal activity: steaming fumaroles and bubbling hot springs; deposits of sulfur, orpiment (arsenic trisulfide), realgar (arsenic monosulfide) and other hydrothermal minerals; and the unpleasant smells of sulfur dioxide and hydrogen sulfide. Fortunately, many of these signs are visible (or smellable) from a distance, and they are also likely to be familiar to the locals.

The borates, on the other hand, seem to occur in deserts. As boric acid-rich waters are evaporated by the harsh sunlight, the borate salts precipitate out of solution, leaving an “evaporite” deposit. We thus would expect to find it in association with other evaporite minerals, such as gypsum and halite (rock salt).

Prospecting for Borates: Knowing What to Look For

The boron minerals are not native to West Virginia. Hence, the prospectors from Grantville are almost wholly dependent on the quality of the descriptions in field guides to rocks and minerals. Fortunately, there are a lot of rockhounds in West Virginia, so there are likely to be several of these guides.

There are two problems with using these reference works. First of all, they are going to emphasize American minerals. The minerals they show might not be found in Europe or Asia. Worse, there may be perfectly useable Old World minerals which aren’t properly identified by these American texts.

Secondly, while the guides often feature photographs, these tend to be of museum-quality specimens. Big, perfectly formed crystals, for example. I am a rockhound, and I can tell you that most of what you find is nowhere near as spectacular as what is in those books.

Two examples should suffice to show what to expect. The Audubon Society Field Guide to North America Rocks and Minerals lists Kernite (sodium borate), Borax (ditto), Ulexite (sodium calcium borate), Colemanite (calcium borate), and Howlite (calcium silico-borate). Each is illustrated by at least one full color plate, and described in terms of its color, luster, hardness, cleavage, specific gravity, fracture, crystal form, and associations. The guide also lists counties where these minerals are found.

The Eyewitness Handbooks Rocks and Minerals lists the first four borate minerals. While it does not provide locality information, it does suggest chemical (solubility, flame) tests for each mineral.

So, what don’t they show? One important omission is Boracite, a magnesium borate and chloride, which is the particular boron mineral found in Germany. Another is Pandermite, a massive form of Colemanite found in Turkey. And a third is Sassolite, which is the crystalline form of boric acid, found in Tuscany.

For boracite, we at least have a description of the crystals in EB11. However, there is no information on the appearance of pandermite or sassolite.

Besides looking for these solid specimens, in Tuscany, we will be seeking out water which is rich in boric acid. That is mostly a matter of taking water samples and testing them for the presence of borate ions (see below).

Assaying Methods

We fortunately have two well-documented qualitative assay methods at our disposal. Both tests are mentioned in the EB11, “Boric Acid.”

The “flame test” was devised in 1732 by C.J. Jeffrey. The suspected borate ore is treated with sulfuric acid (which converts it to boric acid) and alcohol, and the alcoholic solution is then ignited (carefully!). If it burns with a green flame, then the borate ion is present. Sulfuric acid is available in 1632 as “oil of vitriol.” Obviously, it would be prudent to run a “control,” that is, also ignite just the mixture of the alcohol and the sulfuric acid and look at the color of its flame, too.

Lewis Bartolli adapted the “flame test” into a “Mister Wizard” style chemistry demonstration for his presentation to the “Academy of the Lynx” in Cooper, “Arsenic and Old Italians” (Grantville Gazette 22).

Another simple test involves turmeric paper. Turmeric is commercially available in 1632 as a dye and spice; the test paper is prepared by first making up a tincture (an alcohol solution) and then soaking the paper in it. When exposed to boric acid, the turmeric paper turns brown, darkening as it dries. As a confirmatory test, you can add a strong base (sodium or potassium hydroxide), which should turn it almost black.

When Niccolo tells Lewis that Grand Duke Ferdinand wants him to investigate Curzio Inghirami’s claims, Lewis is busy making turmeric paper. Cooper, “Under the Tuscan Son” (Grantville Gazette 9).


The odds are good that each of the up-timers who holds a college degree in chemistry (e.g., Greg Ferrara) owns at least one book on qualitative analysis. I surveyed several such texts to see what they had to say about assays for borate, with these results:

Clifford (1961): Recommends the flame test.

Hahn & Welcher (1968): recommends both flame and turmeric tests, but says neither is extremely reliable.

Fales and Kenny (1955): uses the turmeric test as the principal one, and the flame test only if the former is inconclusive.

Hogness (1957) and McAlpine (1949): no tests listed.


As previously mentioned, one of borax’s down-time uses is in assaying metals in what has come to be known as the “borax bead test.” A third way of testing for borax is therefore to reverse this assay, that is, the suspected borax is used in the bead test to study several known metals. If the correct behavior is observed, then the sample is likely to be borax.

A fairly pure boric acid should be available, in limited quantities, in Grantville. Boric acid powder was used before the Ring of Fire to kill cockroaches. If need be, it could be dissolved and purified further by evaporation and recrystallization. It would then serve as a positive control. The best negative control would be distilled water.

Boric Acid and Borate Collection and Processing

Boric Acid. A small amount of boric acid, in the form of sassolite crystals, could probably be collected merely by exploring the rim of the soffioni and lagone. The boric acid would sublimate out of the vapor as it cooled, or precipitate out of the water as a result of natural evaporation by the sun.

Commercial extraction of the Tuscan boric acid began in 1812. While not mentioned in the available up-time sources, the original method of collecting boric acid from the Tuscan lagone was by boiling the water over a wood fire. Some of the water would evaporate, leaving behind a more concentrated solution of boric acid. This would be transferred into a new pot, and the boil-and-decant process repeated until the boric acid could be purified by recrystallization. The 1911 Encyclopedia Britannica implies that there was a complex network of basins and pipes, with the water flowing “downstream” rather than being pumped, and ending up in what it called “evaporating pans” (probably just very large, very shallow basins).

EB11 says that the initial boric acid concentration was less than 1%. A modern reference work, unavailable in Grantville, says that the average boric acid content of the soffioni vapor is a mere 0.03% (Tincal Trail, p. 24). While the figures seem low, remember this—it was still detectable in 1702 and recoverable a century later.

The description in the 1911 Encyclopedia Britannica is actually based on the improved technique introduced by Lardarel in 1818. He used the steam from the fumaroles, rather than wood fires, to heat the water.

Lorenzo Micheletto pointed out to me that this description ignores the Italians’ lagone coperto (covered spring). In essence, they built a hemispherical masonry dome over a hot spring. The point was to collect the steam issuing from the spring and increase its pressure. The steam was then piped out from the top of the dome, and running under the iron or lead “boilers” which received and evaporated the spring water. According to the Societa Chimica Larderello S.p.A., the covered lagoon technique, introduced in 1829, made possible the increase in production from 50 to 125 metric tons a year.

According to King’s American Dispensatory (1898), a soffione which does not issue into a natural lagone can be surrounded by a masonry wall to create an artificial one. By channeling cold water from a mountain spring into this artificial basin, the steam can be caused to condense.

The next important evolution was to create artificial soffioni, that is, drill to reach boric acid-rich subsurface waters. The 1911 Encyclopedia Britannica mentions this technique, and also that the water coming up the borehole was rich enough in boric acid (by implication, around 2%) to go directly into the “evaporating pans.” By 1940, the Tuscan production of boric acid was 6,500 metric tons a year (SCL).


In 1903, Ginori Conti realized that the geothermal fluids could be used, not only to heat the lagone water, but also to generate electricity. By 1913, Larderello had the first geothermal power plant (250 kilowatts) in the world.

If Tuscany were to become an ally of the USE, it would be very advantageous that it had this ready source of electricity.


Borate. Surface borate deposits, such as those of Borate Lake, can be excavated by pick and shovel.

Chemical Conversions

Around 1815, Payen devised a method of converting boric acid to borate and thereby broke the Dutch monopoly on borate. (EB11/Payen). Boric acid may be converted to borax by treatment with sodium carbonate, or the reaction may be reversed by acidification of borax (sodium borate) with concentrated hydrochloric acid or sulfuric acid. (EB11).

Calcium borate may be converted to borax by fusion with soda ash (sodium carbonate).

Non-naturally occurring borates may be made by reacting sodium or calcium borate, or boric acid, with suitable reagents. For example, the flame retardant zinc borate may be obtained by reacting zinc oxide with boric acid at near-boiling temperatures.

Boron trioxide is made by “strongly igniting” boric acid (EB11).

Amorphous boron was first made in 1808, by reducing boron trioxide with potassium (EB11). It can be prepared in 95–98% purity by reducing boric acid with magnesium and then washing with acid and alkali (EA).

Crystalline boron can be made with difficulty by “reduction of its bromide or chloride (BBr3, BCl3) with hydrogen on an electrically heated tantalum filament.” (EB15). Cotton & Wilkinson (226) warn that its preparation is “a matter of considerable complexity and difficulty even when only small research-scale quantities are required.”

Boron carbide is produced by carbothermal reduction of boron oxide in an electric furnace (EB15) at a temperature of 2500oC (McGHEST), and the nitride by heating boric acid with ammonia (EB15) or borax with ammonium chloride (EB11). (Borazon, cubical boron nitride, which is as hard as diamond, is outside our reach; its manufacture requires pressures approaching 65,000 atmospheres.)

I am not sure that methods of preparing ferroboron are documented in Grantville. It was made in the early twentieth century by carboreduction of iron ore and colemanite in an electric furnace.


I expect that boric acid production in Tuscany will commence in 1635 or 1636, probably on a scale comparable to the early 19c production, perhaps 100 tons annually. The increased production in Tuscany will undercut the Venetian monopoly on tincal from Tibet, dropping the price by at least 50%.

This is going to have an interesting effect on the Venetian economy. Some (merchants in the Levant trade) will suffer, but others (goldsmiths, silversmiths, glassworkers) will benefit greatly. I can’t help wonder whether this will lead to any interesting intrigue.

Tuscany is quite capable of producing several thousand tons annually, and hence there isn’t going to be much interest in developing alternative resources in faraway places (such as the Mojave or Atacama deserts) until demand has ramped up into at least the thousand ton range.

For the glass industry to use a thousand tons of borax, it would need to produce five to twenty thousand tons of borosilicate glass. To put this in perspective, an average mid-eighteenth century French glasshouse might produce 50 to 100 tons of common glass a year (Scoville 20); the largest bottle factory, at Sevres, made about 1,100,000 bottles (850 tons) in 1768 and 1,200,000 (940 tons) in 1788 (14).

To reach the Atacama Desert of Chile, you have to ascend the Coastal Range of the Andes, but at least it’s close to the sea. To reach the borax of the Mojave Desert, you must cross perhaps 70 miles of mountainous terrain.

Turkey is something of the great “wild card”; it has enormous reserves, reasonably close to Europe, but there is no clue in the transmitted up-time literature to the existence of Kirka, and even if there were, the Turks aren’t likely to become aware of it. The Ottoman Empire executes any declared up-timers, and it is uncertain what they will do to a disguised up-timer, or even a down-timer, who makes the mistake of obviously acting on the basis of up-time knowledge.


Boron may not have the glamour of gold. But given the pre-RoF price of borax, and the attractions of borosilicate glass and other boron-based products, it seems likely that quite a few down-time investors will be eager to follow the “tincal trail” to Larderello and, ultimately, to California, the Andes, and Turkey.




[EA] “Boron,” “Kernite,” “Colemanite,” “Borax,” “Death Valley,” Encyclopedia Americana

[EB11] “Boron,” “Borax,” “Boric Acid,” “Volcano,” “Colemanite,” “Tuscany,” “Italy,” “Soffioni,” “Maremma,” 1911 Encyclopedia Britannica

[EB15] “Boron,” “Boron Carbide,” “Boron Nitride,” “Boracite,” “Ulexite,” “Inyoite,” “Borate Mineral,” “Borax,” “Colemanite,” “Searles Lake,” “Payen, Anselm,” “Kernite,” “Lancaster,” “Antofagasta,” “Death Valley,” “Mojave Desert,” “Playa,” “Tsinghai,” “Tuscany,” Encyclopedia Britannica (15th edition).

[McGHEST] “Boron,” “Borate Minerals,” McGraw-Hill Encyclopedia of Science and Technology


Travis, The Tincal Trail: A History of Borax (1984).

Scott, Industrial minerals and extractive industry geology (2002)

Garrett, Borates: handbook of deposits, processing, properties, and use (1998).

Rose, The Metallurgy of Gold (1906).

Hurlbut, Jr., Minerals and Man (1970).

Scoville, Capitalism and French Glassmaking, 1640–1789 (2006).

Stage, Rethinking Home Economics: Women and the History of a Profession (1997).

Daigger & Company, Laboratory supplies and chemicals for chemists and bacteriologists (1919).

Websites—Lardarello Operations

“A Day at Lardarello”


The Geothermal Museum: Larderello (Temporary Headquarters)


The Chemistry




(In Italian)

“I Soffioni Boraciferi ed il Museo della Geotermia di Larderello”


(In Italian)

Societa Chimica Larderello, S.p.A., “The History of Boron at Larderello”


Batini, et al., “Geological features of Larderello-Travale and Mt. Amiata geothermal areas (southern Tuscany, Italy),” Episodes 26(3): 239–244 (Sept. 2003)

Other Websites

[NBRI] National Boron Research Institute, “History of Boron Mining” http://www.boren.gov.tr/en/tarihce.htm

Lyday, “Boron”


[USGS] “Boron Statistics”



GEUS, “Borax replacing mercury in small-scale mining,”