From:
sue <zdome@zzzzzzzz>
Date:
Mon, 24 Oct 2005 08:12:09 -0700
Subject:
blue alabaster
Gypsum is hardness 2 on the mohs scale, while calcite is hardness 3, so
if stone were pure gypsum, it would be softer than a stone composed of
pure calcite. However, most stones contain traces of other minerals (yes
there are 100% pure varieties of both), and other things such as
compactness (density), moisture content, all of which can affect the
apparent "hardness" To add to the overall confusion---there is a form of
non-crystalline quartz (SiO2--hardness 7) that is also known as onyx.
Thanks! I was probably thinking of the quartz as onyx since the stone I
was thinking of was definitely not a 2 or 3 in hardness.
- Follow-ups
- message 00154: quarry photography by Edward Burtynsky - Bill Marsh (24 Oct 2005)
- message 00149: quarry photography by Edward Burtynsky - RPG (24 Oct 2005)
- References
- message 00147: blue alabaster - John Vancamp (24 Oct 2005)
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