The Mineral Gold
…in all its Splendor
"Gold in its natural mineral form almost always has small amounts of silver, and may also contain small amounts of copper and iron. A Gold nugget is usually 70% to 95% gold, and the remainder mostly silver. The color of pure Gold is a bright, golden yellow, but the greater the silver content, the whiter its color is. Much of the gold that is mined is actually from gold ore rather than actual Gold specimens. The ore is can usually be brown, iron-stained rock or a massive white Quart. It usually contains only minute traces of gold. To extract the gold, the ore is crushed and then the gold is separated from the ore by various methods."
"Gold is one of the heaviest minerals. When its pure, it has a gravity of 19.3. Due to its weight, it can be panned, because the Gold sinks to the bottom. It can also be easily separated from other substances due to the weight difference.
Gold is the most malleable and ductile substance known, it can be flattened out to less than .00001 of an inch (that's less than .000065 cm), and a 1 oz. (28 gram) mass can stretch out to a distance of over 50 miles (75 kilometers). Gold is one of the most resistant metals. It will not tarnish, discolor, crumble, or be affected by most solvents. This adds on to the uniqueness and allure of this mineral."
"Iron oxide copper gold ore deposits (IOCG) are important and highly valuable concentrations of copper, gold and uranium. IOCG represents a diverse variety of ore systems, formed in a variety of tectonic settings, geological environments, and with differing ore components. IOCG ore bodies range from around 10 million tonnes of contained ore, to 4,000 million tonnes or more, and have a grade of between 0.2% to 5% copper, with gold contents ranging from 0.1 to 3+ grams per tonne. The tremendous size, relatively simple metallurgy and relatively high grade IOCG deposits can produce extremely profitable mines."
So what is Calaverite? – Calaverite is a combination of tellurium and gold. Calaverite is the name of a tellurium bearing mineral that occurs in specific low temperature hydrothermal veins. It is also sometimes found in higher temperature veins.
Appearance: It is brittle and has a brassy gold to silver white metallic sheen. It’s appearance sometimes confounded old time prospectors who mistookl it with pyrite or arsenopyrite. It commonly occurs in the presence of sulfide minerals. Unlike most Pyrites, Calaverite contains significant gold – about 40% gold by weight. With a 40 percent gold content by weight, you can see it wouldn’t take much calaverite to make for some very rich ore.
A short history about Calaverite and the acclaimed Gold Rush:
Gold Bearing Quartz is one of the world's rarest forms of natural gold. It is found underground by hard rock miners in only a few locations in the world. Most of the World's production comes from a handful of mines in Northern California. This unique formation of very difficult to find "POCKETS" of GOLD in QUARTZ is being mined 1500 to 2500 feet below the earth's surface. http://www.orocal.com/gold_quartz
"Once gold was discovered and the California Gold Rush began, more than 500 camps, villages and towns sprang up almost overnight as some 80,000 prospectors poured into the Mother Lode country in 1849 alone. For more than a decade, the flood of people continued to come, arriving overland on the California Trail, by ship around Cape Horn, or through the Panama shortcut. In the beginning, the miners easily gathered the surface gold, scratching more than $10 million from the land in 1849. By 1853 the yield had peaked at more than $81 million before dropping in 1855 to $55 million."
"Among these tens of thousands of prospectors and an almost equal amount of claims, tales of "lost mines" began almost immediately as pioneers were killed, sickened, or lost their way back to many of the rich ore finds in the mountains and deserts of the Golden State"
"Veins of gold bearing quartz are well known in California, and historically they have produced millions of dollars worth of gold. Their formation and the gold they contain are of interest. Quartz mines are found and worked in a great many counties in California, from Siskiyou on the north to San Diego on the south."
Additional Resources about the history of Gold:
Summary of Gold Mining Techniques in Western United States 1842 – 1996
The Heritage of Gold
"The so-called "auriferous slate belt" of California, of which the Mother Lode is only one part, begins south of Mariposa County and extends north-westerly along the western flank of the Sierra Nevada to the north line of Plumas county, and doubtless farther, but beyond that point it is covered with vast sheets of barren lava. As described, it is about 250 miles long and twenty to seventy miles wide, and forms about one-third of the precious mineral-bearing area of the State, but it is so far the most productive part. The general strike of the strata is north-westerly, which is parallel with the axis of the Sierra Nevada and they dip very steeply to the north-east. Within this area are a countless number of gold-bearing quartz veins, commonly following the strike and dip of the strata, occasionally crossing them."
"Once the ore is mined it can be treated as a whole ore using a dump leaching or heap leaching processes. This is typical of low-grade, oxide deposits. Normally, the ore is crushed and agglomerated prior to heap leaching. High grade ores and ores resistant to cyanide leaching at coarse particle sizes, require further processing in order to recover the gold values. The processing techniques can include grinding, concentration, roasting, and pressure oxidation prior to cyanidation."
Additional Resources about the Refining of Gold:
Refining Gold Explained!
The Mineral Gold
Chemical Formula: Au
Composition: Gold, with small amounts of silver;
sometimes also copper and iron
Variable Formula: (Au,Ag) ;(Au,Ag,Cu,Fe)
Color: Golden yellow to brass yellow
Streak: Golden yellow
Hardness: 2.5 – 3
Crystal System: Isometric