Quartz crystal with striations |
Of course, Dina had to start out with nearly 300 words attempting to describe quartz, including the nonsense line,
"Many experienced rock collectors can tell if a crystal is real quartz through careful examination. They examine the crystal for small naturally accruing [sic] abnormalities (man-made crystals are usually flawless, without abnormalities)."We don't know how abnormalities accrue to a crystal, do you? Be that as it may, Staggs has just the one suggestion for distinguishing quartz from a fake crystal that, she assumes, must be glass:
"Quartz has a hardness of 7 on the Mohs scale, meaning that it will easily scratch glass, metals and softer stones. This test will not harm the crystal if it is real quartz because glass has a hardness of 5.5 to 6.5."Props to Dina for not calling it "Moh's" hardness test! Staggs then goes on to tell her readers to,
"Press the point of the crystal firmly against the surface of the glass. Add a small amount of pressure as you drag the crystal across the surface... Examine the surface of the glass carefully; the scratch will be faintly visible. If no scratch is visible, repeat the test adding more pressure as you drag the crystal..."Sure, that'll work, although it's not really necessary to press the point of a crystal against the glass, any spot will work. Of course, your crystal will also scratch glass if it's any mineral harder than about 6 on the Mohs scale¹, so you haven't really determined whether the crystal is real(ly quartz). So, let's see what other tests Dina says to perform...
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¹ That includes corundum (ruby and sapphire), rutile, chrysoberyl, topaz, zircon, tourmaline, and garnet, among other minerals... oh, yeah: and diamond.
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SI - MINERALS
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