Archive for the ‘Quarries and mines’ Category

Oakland, the city that borax built

24 May 2021

I was taking a bus ride and pondering what to write about for this post, when I looked toward Lake Merritt and found my topic written on the curb: “borax”.

This absurd-looking tag was surely a deeply historical reference to one of Oakland’s most memorable characters, Francis Marion Smith, who became the 19th-century version of a billionaire by exploiting the colossal borax deposits of the Nevada-California desert — and marketing based on the 20-mule teams that once hauled the ore to remote railheads. At least I hope it was, and not a new Oakland gang marking territory.

California is nicknamed the Golden State for the rare mineral that caused the Gold Rush — and the wildflowers too, of course — but Oakland sidestepped the Gold Rush and made its first wealth from the farms, orchards and oyster beds that fed San Francisco. (Its main geology-based industry was crushed rock.) A generation later, Smith became Oakland’s most influential citizen thanks to this boron-bearing mineral from the Nevada desert.

Boron is a cosmically rare element because stars can’t manufacture it, only high-energy cosmic rays that happen to strike oxygen or carbon nuclei in interstellar space. We are lucky that boron is rejected by minerals in the mantle and core and finds a home in the deep crust, mostly in the mineral tourmaline.


Schorl, or black tourmaline, is a boron silicate with a flexible formula that accommodates a wide mix of cations. Clear varieties are prized as gemstones.

In western North America, we’re luckier that crumbling continents and the volcanic activity that follows allow boron to rise to the surface, where it finds even more compatible mates and forms water-loving borate minerals in places like the dry lake beds of the Great Basin. The rise and fall of crustal blocks has decanted and concentrated all sorts of interesting minerals, from common salt and gypsum to lithium compounds and borates.

In the 1870s, borax (Na2B4O5(OH)4·8H2O) was an expensive compound well known to chemists, apothecaries and other specialists, but not at all a consumer good. Then Smith, a Wisconsin native drawn to the wild West, discovered a large deposit of ulexite (NaCaB5O6(OH)6∙5H2O) at Teel’s Marsh, in Nevada east of Mono Lake.


Fibrous ulexite or “TV rock” is available in any rock shop.

He’d seen enough mines by then to know what to do with it: refine it into borax, corner the traditional market for borax in chemistry and medicine, then sell the hell out of borax as the “foundation of a clean healthful home”: a disinfectant, insecticide, home remedy, and cleaning agent for fine clothing, now readily available to the person of ordinary means.

Smith succeeded in legendary fashion: his Nevada claim became the world’s largest borax mine, the first of many he operated, and a new industry was born from the abundance. That gave him the money to buy out his competitors as the opportunity arose and acquire their holdings in the desert. He grew rich; more than that, due to his marketing efforts — for instance, opening a borax shop in New York on Wall Street — he became known as “Borax Smith” at age 26 and, not long after, as “the Borax King.”

Smith moved from the Nevada desert to Oakland in 1881, where he proceeded to put his wealth to work, starting with a large estate and mansion in the Ivy Hill/Bella Vista neighborhood. As he gained experience building and running railroads to serve his desert mines, he consolidated the electric commuter rail lines of the East Bay under The Realty Syndicate, a land development partnership with Frank Havens. The Syndicate owned the majority of the high hills, developed many residential tracts around the Key lines, built the Claremont Resort and Key Route Inn, and planted the ill-fated eucalyptus plantations the length of the Oakland Hills, perhaps the city’s greatest ecocrime.

A hundred years ago, there was no more influential person in Oakland’s urban fabric than “Borax” Smith. The driven, meteoric entrepreneur was memorialized as the titular character Elam Harnish in Burning Daylight, Jack London’s most commercially successful novel: a man whose humanity blossomed not early with wealth, but later through love for a woman.

If only Oakland had borax deposits, or any boron-bearing minerals at all. But it doesn’t. I suppose if it had, Smith would have moved heaven and earth to turn that stuff into money. The only example I can show you is this tourmaline-studded ornamental rock from Pleasant Valley Court.

You might find some at a jeweler’s.

The pyrite orebody of Leona Heights

10 May 2021

Through historical accident (or fate), I’ve been a longtime reader of the late Oakland fiction author Jack Vance. As it happens, Vance was exposed to geology by coursework in mining engineering at UC Berkeley, and one of the most charming and memorable features of his Planet of Adventure series, written in the late 1960s, was the mineralogical currency of the planet Tschai, called sequins.

In volume 3 of the four-book series, we learn that sequins grow in a locality controlled by the alien Dirdir species, who amuse, enrich and feed themselves by hunting the sequin hunters. Sequins come in a range of colors, the clear ones being worth the least and the rare purple ones the most. I no longer have the text in front of me, but I remember them growing out of the ground, literally cropping out. Over at Tor.com, reviewer Paul Weimer does have (and loves) the text and reveals the additional detail that sequins consist of “a uranium mineral called chrysospine.”

The name is mineralogical fantasy, and possibly misleading in that “chryso-” refers to a golden or light green color. But come to think of it, uranium impurities often turn minerals brown from radiation damage, and radiation damage to an originally clear or golden mineral might result in a fair purple by analogy with “sun ripened” glass. An analogy with ripening fruit, too, is irresistible.

In populating his planet with this precious crystalline substance that grows in the ground like mushrooms, Vance evokes truly ancient geological notions that are natural among people who know nothing beyond the most basic alchemy. Gold Rush California saw a lot of that pre-industrial thinking among the amateur prospectors who scoured the state, and the Cornish miners who worked in the hard-rock Mother Lode mines brought along their own ancient customs and superstitions.

In Oakland, the people who exploited the pyrite in the Leona Heights mining district didn’t have the advantage of magic. But Fritz Boehmer, the canny Prussian immigrant who spearheaded mining in these hills, was apparently prone to dreams of earthly wealth, a deep California trait. He was not especially well educated, having apprenticed in metalworking. When he learned of the ore underneath his ocher deposit — one story is that he was digging postholes for a cattle fence, another that “a Japanese” was seeking water for a large fish pond — he thought he had an iron and copper mine, but the professionals set him straight. The copper was only a few percent (although later it was by-produced in paying quantities) and the iron was waste; the money from pyrite (FeS2) was in the sulfur. He let the Stauffer Chemical Company run the mines and gave scientists of the time free access to them.


Pyrite on quartz

The mines ran, interrupted by fires, for about 30 years starting in the 1890s. There were at least three of them. Records are confusing and I’m still trying to sort them out.

The best ore in Leona Heights was in pods of hard, dark, solid pyrite yielding 50 percent clean sulfur that sat, like layers of frosting in a chocolate cake, within a zone 12 to 30 feet thick that tilted into the hillside. The people who published papers about this district scratched their heads at the deposits. They all concluded that the Leona volcanics (“Leona rhyolite” as they knew it) was so jammed with pyrite that the upper part weathered into iron oxides (which stayed behind as the ocherous “iron cap” or gossan) and iron sulfate, which leached down in solution and was reduced back to pyrite beneath the water table in the so-called vadose zone, where it was exposed to a lot of carbonaceous material.


Fine-grained pyrite concentrated in the Leona volcanics, Campus Drive

The trouble with the kind of intermittent research these geologists pursued in the operating mines is that each person who visited the workings saw a different set of rocks. The Leona Heights mines were also prone to fires, so parts were off limits for years at a time, or abandoned.

Henry Mulryan, in a 1925 Master’s thesis, summarized the previous work and consulted their authors, but with several parts of the mines closed off by fires he failed to find any of that carbon-rich rock in the areas he had access to. Unable to prove anything one way or the other, he was forced to punt, saying he would rather wait and see what further digging revealed at depth. “If the Leona Orebody is derived under vadose conditions, then it is the only one known to the writer and should take its place in the world’s literature on ore deposits.” (I too am skeptical about this carbonaceous rock, but the Oakland Hills are complicated here so who knows?)

That was a hundred years ago, before geologists made huge strides in understanding this class of “volcanogenic massive sulfide deposit,” not to mention a scientific revolution, in the years between then and now. Meanwhile the mines are long closed and will never be reopened. The samples, if they still exist, are gathering dust in obscure cabinets. I’ve read all the contemporary literature (except for some theses — Leona Heights seemed to be a handy subject for Stanford and Berkeley students at the time), which is an absorbing chore because the records are sketchy by modern standards and the terminology has changed. But there are rewards; Mulryan had some good photos of the Leona sulfur mine circa 1924.


Looking west on the Leona Mine. The hook in the road is at the end of McDonell Avenue. The rail line carried ore cars to the crusher, then to a 1600-foot aerial tram that carried the ore to the train in Laundry Farm canyon. Chabot Observatory in the background.

I’m still scratching my head about the Leona Heights pyrite, and I find myself envying Jack Vance’s freedom of imagination. Reality can be tough; you can’t just make up something wonderful.

Boothite: Oakland’s own mineral

21 December 2020

This is the story of two Germans and their meeting long ago in Leona Heights.

Fritz Boehmer was a Prussian, born in 1831 in Magdeburg and trained in ironworking in his father’s foundry. In 1848, word arrived in Europe about fabulous deposits of gold in California, on the opposite side of the world. Europe was bursting in liberal-led revolution that year, shaking the continent’s political foundations from end to end and overseas. It was a restless time. When Fritz’s brother Eduard joined a group planning to sail to the gold country, Fritz begged leave of their newly widowed mother to see his brother off in Bremerhaven — and then climbed aboard himself, landing at San Francisco six months later as the world rushed in. In 1851, a shrewd and lucky man just twenty years old with a small fortune in gold, Boehmer bought a 160-acre plot in what is now downtown Oakland and embarked on a busy life that did not end until his death in 1910 and burial in Mountain View Cemetery. He was known for his generosity, good humor and love of song.

Boehmer was a founding father of the city of Alameda and had his home and main business there, a grocery, but he took a keen interest in his 92-acre holding in the hills east of Oakland along the old road to the redwoods, in the headwaters of Lion Creek behind the scenic grassy valley long known as Laundry Farm. He liked to call his place Friedrichsruhe, after Count von Bismarck’s country lodge near Hamburg, and his parties there were reported in the newspapers. (The papers and Boehmer’s 1904 reminiscence are where I learned most of the information in this post.)

Boehmer cast a shrewd eye over his land on Redwood Road, particularly its springs. He seized upon a story about Lion Creek told by an old Indian, who recalled that Lion Creek had roared with water after the major Santa Cruz Mountains earthquake of 1838. Although this phenomenon is now widely known among earthquake geologists (and my regular readers), Boehmer took it to mean that his land held a large underground river, and if he could tap that reservoir he could enter the water business.

In the 1890s his attention turned to the large natural deposit of ocher on his land, formerly a major resource for the Ohlone tribes and their trading partners. Soon he erected a mill at the site and launched a factory in Alameda that turned the ocher into “a good article of domestic paint.” The mill burned down a few years later, but by that time the deposit was nearly played out. Besides, he was busy subdividing his land and managing a hotel by Redwood Road, which he had paid to reroute at a lower grade. (If you can believe it, the old “blue road” was even steeper than today.)

Boehmer continued to keep his eye on the ground. In 1898 he was showing people chunks of rock from underneath the ocher, bearing veins of yellow metallic minerals, and spoke of mining gold and copper. That was the year when Laundry Farm was rebranded as Leona Heights by real-estate schemers with a plan to run an electric rail line there and sell lots to individual homebuilders.

By 1900 he had opened the Alma Mine, named for his daughter, and was selling trainloads of pyrite (the yellow mineral in question) to a chemical company that manufactured sulfuric acid from it. The professors of geology and mining and chemistry at UC Berkeley were visitors to his mine, and that’s how he met the second German.


View of Redwood Road from the west, 1949. The Alma Mine entrance was north of the road behind the trees. Oakland Library History Room image.

Waldemar Schaller was actually German-American, an Oakland native born to immigrant parents in 1882 and still living at home while he attended the Cal mining college. He undoubtedly spoke German at home. Later he described his early years: “As a boy I found my greatest pleasure in roaming over the hills around San Francisco Bay, collecting minerals and rocks, making many trips to Tiburon Peninsula hunting for lawsonite . . .” It was Andrew Lawson himself who nurtured his interest in geology, and Edward Booth of the chemistry department who introduced him to the Alma Mine.


Fritz Boehmer in 1901; Waldemar Schaller in 1939 (S. F. Chronicle/Mineralogical Society of America)

The brilliant young student of mineralogy got along well with the jovial old mine owner, who gave Schaller the run of his specimen collection. In 1903, still an undergraduate, Schaller published a 17-page paper in which he described the crystallography and chemistry of a dozen different copper and iron sulfide and sulfate minerals (plus red and yellow ocher) from the mine.

One of them, a delicate sky-blue hydrated copper sulfate, was new to science, and after providing a full description of its characteristics Schaller gave it the name boothite and established the Alma Mine as its type locality.

Later that year, Schaller won a position with the U.S. Geological Survey and remained there for the rest of his long and illustrious career. He described and named an impressive 41 minerals before his death in 1967. Boothite was his first — the kind of early triumph that can put someone on an epic path of achievement.

A few specimens from this historic locality are still extant. Maybe some have been handed down to living Oaklanders.

The changing identities of the Leona Quarry

9 November 2020

Last week I finally gave in and returned to the high hills — for exercise, as permitted by the county health authorities — and couldn’t resist a reconnaissance of the Leona Heights area. It’s Oakland’s boldest and most rugged region. Here it is from Knowland Park, above the zoo.

Most Oaklanders may know it, though, as the mountainside with the huge scar on it overlooking I-580, the former Leona Quarry.

The quarry was first opened by the Ransome-Crummey Company in 1904 and ended operations under Gallagher & Burk in 2003, but it changed hands (and names) several times over the years, making its detailed history hard to trace. Also, newspaper accounts often confuse it with the Leona Heights quarry, which was at the site Merritt College occupies today.

The quarry was first made feasible by an extension of the Laundry Farm railroad, above Mills College. It was originally high up a steep grade, as shown by the pick-and-hammer symbol in the 1915 topographic map.

I believe it was up there because the bedrock was well exposed, making excavation unnecessary at a time of heavy reliance on hand labor. The 1947 map shows that operations had moved downhill, and quite a bite had been taken out of the hillside.

And the 1980 update of the 1959 map shows the quarry scar at its ultimate size.

The whole time, this hillside was being quarried exclusively to make crushed rock. There was a huge demand for coarsely crushed stone in the days before asphalt and concrete pavement. The gold standard for city streets in the late 1800s and early 1900s was macadam, which has completely disappeared since then. You’ll only see it in silent movies.

A macadam road started with a shallow excavation that was filled with several layers of crushed rock, of successively finer grade, topped with fine gravel or rock dust. The jagged, blocky texture of crushed rock made macadam roads exceptionally firm in comparison to plain dirt or gravel, and they didn’t turn to mud in the rainy season.

As Oakland grew, filling in the harbor and airport and covering East Oakland with suburban tracts on an ambitious street grid, its quarry owners prospered, especially the well-connected ones who could arrange favorable contracts and keep wages low. Plain old crushed rock — road metal — was in high demand. Although there were still good markets for crushed rock after the macadam era ended, things were not the same. The Leona Quarry outlasted all of its competition in Oakland thanks to its remote location, good rail transport and ease of production. But eventually the city expanded to the quarry’s doorstep, the quarry ran out of easy rock and the show ended in 2003, when I took this shot of the north end of the property.

That’s when the site took on its next identity — a townhome district. The rock no longer matters.

But it used to. I think the Leona Quarry started running into problems as the standards in the rock business grew steadily stricter.

Leona Heights, the mountain, consists of a body of much-altered volcanic material of Jurassic age that I refer to on this blog as the Leona volcanics. Its eventful history left it impregnated with pyrite, iron sulfide, in many places. A little farther northwest, in the valley where route 13 splits from I-580, there was enough pyrite to support at least two mines. Down at the Leona Quarry there wasn’t as much, but it does exist and, as it does in the old mines, pyrite decays in the air and rain into iron oxides and sulfuric acid. The oxides turn brown, staining the Leona volcanics this typical color.

They also stain the stream water, as seen here in the headwaters of Chimes Creek above the quarry (and elsewhere in the hills).

The west side of the quarry was full of this “red rock” while the east side consisted of a dense blue-gray siliceous rock, more like this specimen I collected there back in 2009.

Whereas the red rock was useless for things like concrete aggregate because of its pyrite content, this was the good stuff. Nevertheless, the market for excellent road metal came to be dominated by huge outfits like Granite Rock — whose co-founder, Arthur Roberts Wilson, started his career at the Leona Heights Quarry back in the 1890s.

Meanwhile today, the former quarry is now a townhome plantation, set at the bottom of a high, steep rocky bowl.

There is no guarantee that the quarry’s second identity will last forever. Fire, earthquake and rockfalls can overcome any defense given enough time (although the Leona Quarry development has a GHAD that maintains the defenses). Zoning changes and real-estate fashions can undermine such enterprises as surely as physical hazards. There is no guarantee that anything we build will last a century, like the quarry did. Like the ancient philosopher said, everything flows.