THE WORLD OF NATURAL GOLD QUARTZ

 Welcome to the world of natural Gold Quartz. For the uninitiated, GQ, essentially, is gold ore found in the earth's outer crust. It's recovered from hard rock lode mines, as placer, and float rock (displaced, loose pieces of freed-up ore). When geological conditions create the right habitat, metallic and non-metallic mineral solutions carry dissolved gold and quartz (silicon dioxide) through passageways within the earth's mantle. These days, fluidization is the operative word used by exploration geologists. Faults, fissures, and shear zones are contacts where major rock formations come together. These contacts act as conduits for mineral-rich fluids. During cataclysmic events such as volcanic eruptions, an enormous variety of minerals are mobilized and pushed upward. Eventually, these minerals cool down and crystallize. In many regions around the planet, volcanic activity remains incessant. Where terranes, expansive blocks of land remain in constant motion spreading out across the ocean floo, vents release gas and fluids. In the process, metallic minerals are deposited. This, then, is how classic quartz vein lode deposits form. 

Silicate quartz veins, however, are not the only ore bodies to host gold deposits. During the past fifty odd years, a handful of pragmatic geologists started thinking outside the box. They theorized that other types of auriferous lode deposits could exist. After extensive and careful core drill analysis, they discovered that high-pressure, percolating fluids invading permeable sediments had been producing massive lode deposits all along. The gold was microscopic in size, but it was there - in highly-profitable and minable amounts. Eventually, geologists went on to discover even more diverse gold provinces. 

 Placer gold in a 'free state' isn't generally associated with micron gold deposits. It originates from fissure-type quartz veins. Gold in quartz veins tends to be more concentrated. That's why authentic gold quartz specimens show Au while other types of gold ores don't. At the start of the California gold rush, the 49ers were chasing this 'free gold' i.e. placer gold. Being basically soft and malleable, larger pieces, once they've broken off and separated from their mother vein, take on unique, interesting shapes. Character is imparted to each piece. Even the most featureless gold flake won't be without it's distinctive marks. Vein filling which retains the host matrix rock (gangue) and harbors metalliferous gold also can become one of the earth's more highly-prized gemstones. I deal in this material as well as in specimen-grade GQ. Again let me convey  the value of GQ specimens is not in how much gold they contain. Their value lies in the fact that gold is there; visible to the naked eye; the product of dynamic, elemental forces in the earth's crust.

 

The ideal criteria for GQ gemstone is hardness, richness, and color. The best grades of gem rock are dense, unbrecciated, and contain minimal cracks or fissures. The commonest quartz color is white. Personally, I prefer the vari-colored ores. Through the years, I've come across an unbelievably-broad spectrum of matrix coloration. From them, I've been creating cabochon gems utilizing this broad spectrum of colors. Harder cryptocrystalline quartzes containing gold, where found, are highly-prized by gemologists/lapidaries/jewelers/and collectors. Overall mineral compositions and characteristics of GQ varies from district to district. This results in a variety of differently-colored matrix (host rock) occurrences. The fineness/karatage of the Au differs as well. This effects both the gold's color and it's purity.  

 

The metallic mineral, gold, occurs in many different geological formations. Within the U.S., Nevada, in particular, has become a world-class, gold-mining juggernaut. In modern-day mining operations, entire mountains are blasted down and piled into heaps. Oxide Ores are soaked with cyanide solution, an acid which leaches precious metal from these ores. Other types of ore also exists. Chief amongst them are carbonaceous and sulphide ores. Within these groupings, different processes are utilized to concentrate and extract the gold. 

 A century ago, a more-likely scenario went kinda like this. Some lone-burro prospector liked the looks of a quartz outcropping. Spotting some section of the ledge which was more friable then the rest, he chipped samples off of it. Maybe his pack animal (donkey/mule/horse) carried all the necessary equipment for performing fire assays. At the very least, he would have been outfitted with a mortar, pestle, and gold pan. Once his samples were crushed, maybe a good line of color remained in the pan. Encouraged by the result, he commenced to sink a shaft into the exposed quartz vein. Perhaps he drove a tunnel horizontally or on an incline. It all depended on what strike the vein had taken. All this, of course, was accomplished using basic hand tools unless he had dynamite. Just placing charges to shoot the rock took countless man-hours of single-jack drilling. This was unimaginably-hard work. Well, actually, I can imagine it. After ore had been mucked and hauled from the mine-shaft, it needed to be crushed. In that manner, the gold was freed up. Production was slow to put it mildly. Maybe our prospector used a 'dolly pot' or some sort of improvised arrastra. With his primitive tools, only the most readily-identifiable high grade would be processed i.e. crushed and milled up. Could be ore from his new mine was hauled off on a pack team to some far-away millsite better equipped to handle the volume. If gold was visible in the rock, that obviously would have qualified as ore rich-enough to crush.

 

As mentioned, arrastras were used in earlier times to pulverize ore. After it’s release, depending upon the practices commonly in use at that particular time and region, gold was most-likely sluiced (using water) or amalgamated using 'quick' i.e. mercury. Later-on, stamp mills arrived on the scene. These replaced the more antiquated methods improving and speeding up the rate of gold extraction. Though noisy, toxic contraptions, they did increase production a hundred-fold by multiplying how much ore could be crushed and milled. Because of silica dust, an extremely-hazardous by-product, some mines were branded 'widow-makers'. Dust ingested by humans over a prolonged period of time becomes lethal inasmuch as it causes the gold miner's version of the dreaded black lung disease. It's a historical fact that silicosis filled many cemeteries. Try to imagine clouds of finely-powdered silica enveloping both workers and townspeople day and night.

 

In the old days, the classic, lone-burro prospector's first inkling of a lode was usually an exposed quartz ledge. This wasn't always the case, but many times it was. Miners digging rich placer below some vein system, one bleeding out coarse, gnarly, crystalline gold into the surroundings, understood that a local vein system was the most likely source. Today, core drills are the main geo-exploratory tool used to test the tenor of rock at depth. Many fissure-type lode deposits such as the Homestake Mine in South Dakota and California's Sixteen to One Mine were followed deep into the earth. Oftimes it happens that prior earthquake slip episodes cause productive veins to abruptly disappear. Their position in the earth is rendered unreadable and unknown. In such instances, if the ore body was panning out handsomely, miners undoubtedly would make attempts to relocate their lost lead. Sometimes, they were successful, but often they were not. Past movement in the earth's outer crust over long periods of time reshapes it's internal morphology. In-situ veins shift to unpredictable positions. Mountainsides are adept at hiding their treasures. As history relates, many rich leads were lost perhaps never to be found again. There's no shortage of reasons why deep quartz fissure mines become unprofitable. Water seepage was another major challenge encountered by miners. Prices for metals also fluctuate. Many factors influence the availability, production, and profitability of gold quartz mining and the end product itself. Only a scant handful of mines around the world produce gem-grade material. Even when a new deposit is found, collectors and dealers are tasked with procuring something not publicly offered or made available by the mines themselves.