California Gold
California and gold are intimately linked in the minds of millions. To those with a special interest in minerals, though, the link is more particularly between that state and its fine specimens of crystallized gold.
BY WAYNE AND DONA LEICHT
When John Marshall noticed several small, bright yellow, metallic lumps in the millrace of a partially completed sawmill on the south fork of the American River near Coloma, California, on January 21, 1849, he certainly did not foresee the incident’s vast consequences. This seemingly unimportant discovery would prove to be the spark that would ignite a series of events leading to the largest gold rush in the history of the world.
No other single event in the history of California has had such a profound impact on the early economic development of our fledging nation and the realization of President Jefferson’s concept of Manifest Destiny. The enormous revenues from gold pouring out of California transformed a lackluster economy of the post-Mexican War era into a vibrant period of industrial expansion that later was to evolve into the American Industrial Revolution. The thousands of Americans (Yankees as they were called) and foreign fortune hunters who flocked into the Sierra Nevada foothills and mountains in the early 1850s most certainly expedited the early statehood of California and secured the area once and for all from the possibility of Mexican re-occupation.
During the early part of California’s gold rush most of the gold from the area was in the form of nuggets. Nuggets are, for the most part, just lumps of gold that have weathered out of the host rock and have been worn smooth by abrasion against rocks and sand. The weathering and transport mechanisms are usually water, but wind, earth movements, and gravity can also play an important part in both shaping and transporting gold nuggets.
Nuggets are often found some distance from where gold was initially deposited. In the case of many California deposits, the ancient streambeds have long since been buried by other sediments and uplifted high above present-day water courses. These ancient streambeds are called tertiary channels and were the source of some of the most important placer mines in the state (placer) comes from the Spanish word meaning plain or plaza, but no one seems to know quite what the connection is, although a number of possibilities have been suggested).
Gold, because of its high density (a specific gravity of 19.2, or nearly 20 times as dense as water), tends to sink to the bottom when in streams and thus is most often found on or near the bedrock of a stream. Likewise because of its density, gold is relatively easy to separate from any surrounding rock and gravel.
Called the Argonauts (a reference to the ancient Greek story of the hero Jason and his followers aboard the ship Argo; they traveled to the Black Sea in search of gold in the form of the legendary Golden Fleece), the early California gold miners found that the gold nuggets near the surface could be extracted from the alluvial material using relatively primitive devices such as gold pans, rockers, and sluice boxes. One needed only a source of water, a promising claim, and a willingness to work and the gold was theirs for the taking.
These early methods of mining were inefficient and extremely labor intensive. Gradually, these small one- and two-man operations gave way to the larger, better organized mining companies that employed a much more environmentally devastating method of mining known as hydraulic mining. In some areas, particularly in the northern part of California’s Mother Lode – a narrow, well-defined vein system that extends from Mariposa County in the south to El Dorado County in the North – whole mountains of rocks and gravel were literally washed away by jets of water from a nozzle called a monitor.
After the gold was separated from the gravel, the debris was allowed to redeposit downstream, choking other streams and filling canyons. Large lakes were drained to supply water for some of the largest operations. This type of mining was outlawed by the government, but the devastation from hydraulic mining can still be seen today – over 125 years later!
As the rich surface workings became exhausted in the Mother Lode, the miners began looking for the gold’s source. Often they noted that as they worked their way up the larger streams into the smaller tributaries, the gold nuggets were larger and showed less wear. Knowing that the amount of wear on a nugget was an indication of how far it had traveled, they suspected that they were near the source. Similarly, if they suddenly stopped finding nuggets, they suspected they had worked their way past the source.
This method of “reading the ground” was responsible for the discovery of many important lode mines in California. “Lode” is a term used to denote minable gold in the host rock, usually quartz, and hence a lode mine (sometimes also called a quartz mine), is where gold is mined in situ. Lode mines are often underground mines and can be quite extensive and deep.
Other deposits were discovered quite by accident. The guidebooks to the Mother Lode are full of stories of how rich lodes were discovered. A lode near Angels Camp, as the story goes, was discovered when a Mr. Strawberry got his ramrod stuck in his rifle and attempted to free it by firing it at the ground. The ramrod struck a piece of quartz exposing the gold! “Strawberry Lane” exists today as a street in Angels Camp in Calavaras County as a testament to the local folklore.
Within three or four years after Marshall’s initial discovery of gold, the type of mining in California had shifted from small independent miners and mining companies to large, well-financed operations employing at times thousands of miners. The gold from this type of mine is almost always associated with quartz and occasionally other minerals such as pyrite, arsenopyrite, galena, calcite, and other minor minerals. In some of the richer gold mines, the gold is so finely disseminated throughout the rock that it is difficult to see without magnification.
Mines in which the gold is in “pockets” of several ounces, are, as one might guess, called “pocket mines.” The famous 16 to one mine in Sierra County is just such a mine. Several pockets in that mine contained over 10,000 troy ounces of gold! Such pockets, though, in even the largest of the California mines, are exceedingly rare.
The classic pocket mine is a small, localized, high-grade deposit often near the surface. The gold will be easily mined but the total overall amount of gold from such a mine is usually small.
Occasionally one of these small pocket mines will produce some crystallized gold. This type of gold is extremely rare and sought after by collectors for its rarity as well as its beauty. Although crystallized gold has been found in other gold mining districts throughout the world, California has unquestionably produced more and better examples of this type gold than any other region in the world.
Crystallized gold is not always easy to recognize, even though it crystallizes in the simplest of the six crystal systems: the cubic system. The most common form in the cubic system is the simple six-sided cube with interfacial angles of 90 degrees. “Fools’ gold,” or pyrite, is often found in this form.
Gold from California, however, is rarely found as simple six-sided cubes; more often, it is found in modified or distorted octahedrons. The ideal octahedron can be visualized by placing a pyramid base down on a mirror to show a mirror image of itself. Perfect octahedrons of gold, showing bright, smooth, well-formed crystal faces, are extremely rare; especially so if they are of any substantial size. Most often the crystals are distorted, flattened, or show elongated growth along the faces parallel to the triangular faces. Modification of the simple octahedron by the cubic faces and other less symmetrical faces also adds to the confusion.
Leaf and dendritic gold are both examples of gold crystallized in the octahedral habit where the growth of the crystal is extended parallel to the triangular faces of the octahedron. If a leaf of gold is examined microscopically, almost always one can observe small raised triangular faces on the surface.
Wire gold, or gold that looks like it was squirted out of a toothpaste tube, is more complex form of crystallized gold and is often mistaken for gold that has been extruded through a hole. Wire gold specimens are examples of what is called spinel twinning in gold, where the individual barbs (like sharp edges often exhibited in spinel twins of copper and silver) are so small as to appear smooth.
Wire gold from California is very rare and to our knowledge has been observed only in a few specimens; even rarer is a specimen showing both wire and leaf gold, such as one in the authors’ collection. Colorado, on the other hand, has produced several fine examples of wire gold from both the Breckenridge area and the Ground Hog mine near Gilman. Examples of fine gold specimens in various forms of leaves, wires, and dendritic crystals are pictured, and all are various forms of the octahedron crystal habit.
As early as 1850, a few water-worn gold crystals had found their way to the East Coast and were described in the Journal of Science and Arts by Francis Alger of Boston, Massachusetts. He described them as rather large, unmodified octahedrons with slightly depressed centers on the triangular faces. In his article, he indicated that there was some discussion as to whether these were actual crystals or pseudomorphs of gold after another mineral. Alger indicated that he was “not disposed to ascribe any such forced and unnatural origin to these beautiful productions.”
Apart from a few vague references to “specimen gold” and “jewelry gold” in various county and state reports, very little was written on the subject of crystallized gold from California until 1885, where buried in an obscure report from the Director of the Mint is a short but superb paper entitled “The Various Forms in Which Gold Occurs in Nature.” The paper was written by William P. Blake (after whom the mineral blakeite was named) while he was employed as a geologist for the California State Board of Agriculture. Blake described the various forms in which gold occurs in nature with particular emphasis on the crystallized gold from California.
Several fine examples of crystallized gold found during the California Gold Rush can be found in some of the older institutional collections such as the Harvard Mineralogical Museum collection in Cambridge, Massachusetts; the Peabody Museum at Yale University, New Haven, Connecticut; and the California State Mining and Mineral Museum in Mariposa, California.
Contemporary examples of contemporary crystallized gold can also be found at the Smithsonian Institution, Washington D.C.; the Los Angeles County Museum of Natural History, Los Angeles, California; the American Museum of Natural History, New York City, New York; and the Denver Museum of Natural History (Colorado gold), Denver, Colorado.
Old specimens in private collections, traceable to the 1850s and 1860s, are rare, probably because few collectors were around to save specimens. Occasionally, an heir of one of the early pioneer mining families will dispose of a collection, releasing some specimens into the marketplace. This material is eagerly sought after by collectors and museums alike.
Several fine private collections do exist, however. More often than not, private collectors of gold like to remain anonymous and rarely show their collections. Good examples of crystallized gold are noticeably absent in old European museums and private collections, even though many were in existence and active long before the discovery of gold in California. Even the British Museum of Natural History in London, England, has only a token representation of gold from California.
In a discussion of the mines that have produced crystallized gold, one needs to remember that occasionally it is found in a mine where the gold is normally finely disseminated in the quartz. The Empire, the Idaho-Maryland, and the North Star mines, all in Nevada County, have occasionally produced some remarkable examples of specimen gold completely out of character with the normal production. Other mines in the central and southern part of the Mother Lode have done likewise. Perhaps the best example is a specimen from the Empire mine in the American Museum of Natural History. It is a rather large piece with no matrix showing small intergrown leaves and octahedron crystals—a unique piece from this mine not noted for collector specimens.
Many gold specimens in both private and museum collections are mislabeled. Often this is deliberate, the result of an effort to conceal the true source of the specimen because it was “high graded” by some enterprising miner with a little side business in specimens. Other problems are the result of a “best guess” as to the locality data on the part of a previous owner. Adding to the problem is the consolidation and renaming of smaller mines into larger operations.
An example of the latter is the consolidation of the Tightner, Orphir, Red Star, Twenty One, South Fork, and the Rainbow mines into the present day 16 to 1 mine in Sierra County. Small amounts of crystallized gold were found in the early working of both the Red Star and the Rainbow mines, yet the 16 to 1 mine as a whole is not noted for producing much in the way of fine, well-crystallized gold specimens.
As a general rule, the larger, deep lode mines of California produced little gold showing well developed crystals. Pocket mines have supplied the bulk of the really fine specimens found in collections. Most of the specimens found in private collections and museums came out during the height of mining activity in California between 1848 and 1942. Most of the lode mines were shut down by an act of Congress during World War II.
Recently a few small pocket mines have been operated more or less successfully and have supplied the collector market with some specimens. The Colorado Quartz mine and the Diltz mine, both in Mariposa County, produced some remarkable specimens some years ago but have not produced much in the past few years.
Most of the present day mining activity for specimen gold is concentrated in the Michigan Bluff Mining District in Placer County. The so-named Eagle’s Nest mine in the district is the only mine that has consistently produced fine examples of crystallized gold. The mine is a small, rich, localized ore body and is typical of the pocket mines of the district.
The gold occurs near the surface (100 to 300 feet) in a narrow, almost horizontal, quartz vein system with minor amounts of sulfides in the form of pyrite and arsenopyrite. In some of the quartz veins, all of the carbonacious rock has been naturally leached out, leaving the gold almost loose in the fragmented quartz veins. Specimens from this area of the mine tend to have little or no quartz associated with them. In areas of the mine where no leaching has occurred, the specimens have more quartz matrix.
The country rock is mostly decomposed shales and greenstones laced with quartz veins. The mine produces very little mill rock, that is, rock that is crushed and from which the gold is extracted and sold for bullion value in that almost all of the gold is of specimen quality. Several other mines in the district are more or less active, but this mine has certainly produced the largest and best crystallized gold found in California in the past 30 years.
It is difficult to describe a typical specimen from the mine. In some veins the gold is lacy, bright, and dendritic, with no matrix. Other veins produce large, heavy, flat specimens with areas showing sharp distinct octahedrons and leaves. The only consistent characteristic of the gold from the Eagle’s Nest mine is that the specimens tend to be flat, having formed in the narrow quartz veins.
Historically, one of the most famous mines for crystallized leaf gold has been the Red Ledge mine, located in east-central Nevada County. Like the Eagle’s Nest mine, this is a shallow pocket mine. Most of the gold from the Red Ledge is in the form of bright dendritic leaves. Much of the gold was found loose in quartz cavities associated with feldspar and clear quartz crystals.
Very little is known about the early output of the mine. In 1952, it was purchased by Sam P. Tracy. Mr. Tracy worked the mine for specimens until his death in 1968. We do know that the mine produced some fine specimens prior to 1952, as indicated by an extremely fine specimen in the collection of the Cranbrook Institute of Sciences, Bloomfield Hills, Michigan, which was acquired shortly after the turn of the century. However, specimens attributed correctly to the Red Ledge mine prior to 1952 are few.
Many of the specimens from the Red Ledge mine mined between 1952 and 1968 were purchased by the late Charles Crespi, a banker in Angels Camp, Calavaras County. His collection was without a doubt the finest private collection of California crystallized gold ever assembled. The entire collection was purchased by Kristalle in 1968, and a number of the most fabulous pieces are now in the Smithsonian Institution collection, as well as other museums and private collections around the world.
The Grit mine in the Greenwood District north of the town of Georgetown has the distinction of having produced what is probably the largest mass of crystallized gold ever found in the state: the “Fricot Nugget.” The mine was formerly known as the Spanish Dry Seam mine after the Spanish who worked the area in the 1850s without water by carrying the gravel to a nearby stream for washing. Later the Grit mine was worked by hydraulic mining methods and the bottom of the pits mined as lode mines.
It was in the area mined as lode mines that the Fricot Nugget was found in 1865. The Fricot Nugget (actually it is not a nugget at all but rather a mass of crystallized gold) weighs 201.4 troy ounces and is composed of intergrown octahedron crystals up to a quarter inch on a side. Although it is broken into three pieces, the Fricot Nugget is considered by some as the finest specimen of crystallized gold in existence. But for this single specimen, the Grit mine would have passed into obscurity as have thousands of other mines from the gold rush era.
Small pocket mines from which only one remarkable specimen was found are common in the central part of the Mother Lode. The Eureka or Harper Brothers’ mine in Tuolumne County is an example. The claim was first located in 1893 or 1894 by Edwin F. and Charles F. Harper in Grizzly Gulch. They worked it intermittently until the middle of the 1940s.
In 1949, a single mass of crystallized leaf and octahedron gold was found measuring six inches wide by 13 inches long and weighing 67 troy ounces. It was found in a bed of talc with loose quartz crystals just a few feet below the surface. The aforementioned Mr. Crespi purchased the specimen and after his collection was broken up it was sold to the Smithsonian institution and is on display there.
There will always be occasional deposits that will produce a specimen here and there, and these deposits could be in any area of the world, but without a doubt California still reigns as the prime source for the best of crystallized gold. Historically, the romance of gold is so closely linked with California that it will most likely stand in perpetuity.
Recent deposits in Papua New Guinea are promising due to the sheer quantity of gold they produce, but much of it is dull in color and without matrix, and few specimens of great size have been recovered. However, the crystallization is quite distinctive and worthy of a collector’s interest. Specimens have also come to the marketplace from Venezuela, and many of these show interesting crystallization (although water-worn and dull), but again, have no matrix associated with them.
The lore of gold will never cease. It’s one of the few names recognizable to people the world over—men have lusted after it, countries have gone to war over it, world economics are linked with it. The list goes on. But it is probably “the dream,” the chance to “hit it big,” that will keep men digging for gold. We’re fortunate that miners today are aware that some gold specimens have value greater than its intrinsic value. We can only hope that they will have the foresight to save these beautiful objects of nature for all of us to enjoy.
Wayne and Dona Leicht are owners of Kristalle, kristalle.com
