New at Rosetta Stones: How to Find Gold in Fool’s Gold

Dana Hunter

There’s gold in them thar pyrites – no foolin’! In my very belated follow-up to our Fools for Fool’s Gold, we learn how to find the invisible gold in (some) pyrites.

I'll let Rob describe it for you: "An AMAZING cluster of quartz crystals out of the collection of Ed David! These gemmy crystals are stacked upon one another as if by hand, with both terminations complete, sticking out on either side! The terminations on one side of the crystals are sprinkled with little yellow-tan muscovites. On the other side is a cluster of arsenopyrite (the quartz/arsenopyrite association is well-known from this locality). A show-stopper of a quartz specimen!"
A gorgeous hand sample of exquisite quartz crystals and shiny arsenopyrite. Photo courtesy Rob Lavinsky / iRocks.com (CC-BY-SA-3.0).

See why I wouldn’t pubish that story anywhere near April Fool’s Day?

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New at Rosetta Stones: How to Find Gold in Fool’s Gold

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4 thoughts on “New at Rosetta Stones: How to Find Gold in Fool’s Gold”

  3. rq
    3

    New project: smacking all collected samples of pyrite with a hammer, and waiting for that delicious smell of garlic gold.

  4. lyle
    4

    Actually according to this report: pubs.usgs.gov/circ/1969/0610/report.pdf All rocks contain some gold in the parts per billion range: “Igneous rocks contain as little as 0.2 and as much as 73 ppb
    (parts per billion) gold. The average, calculated on the basis of
    50 percent granite and 50 percent basalt, is 3.0 ppb. Averages
    (in parts per billion) for individual plutonic rock types are: granite,
    2.8; syenite, 2.5; diorite, 3.5; gabbro, 5.4; anddunite, 8.2. Averages
    (in parts per billion) for individual volcanic rock types are: rhyolite,
    12; trachyte, 6.5; andesite, 5.2; and basalt, 3.2.
    Sedimentary rocks contain as little as 0. 3 to as much as 41 ppb
    gold. The average of 5.0 ppb is based on the average of 7.5 ppb
    for sandstone, 3. 9 ppb for shale, and 3. 5 ppb for limestone.
    In metamorphic rocks the range of gold content is from 0.86 to
    22.4 ppb with an average of 4. 3. The average (in parts per billion)
    for gneiss is 1.8; for schist, 5.0; for quartzite, 4.8; and for marble,
    3.1.”

    So all rocks contain gold all be it in quantities that it would take a mass
    spectrometer to find. (Just like sea water contains gold in the
    parts per trillion range)

    The trick is that hydrothermal fluids pick up the gold from the parts per billion
    content level in the country rock because gold dissolves out of rocks fairly easily
    in hot and high pressure conditions and tends to be a late stage precipitator
    out of the fluids, Thus quartz veins containing gold such as California’s mother lode
    country as well.

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