Compounds of stone

[stefchris@xxxxxxxxxxx (Christian Schneider)]

hi there,

I am a geologist but not sculpting, here are some
compounds of stone you have been asking for:

marble = CaCO3
It is a kind of limestone that was transformed by heat
and pressure (of overlaying rocks)

limestone = CaCO3
chemically the same as marble but not transformed by
heat and pressure, usually a sediment that grew out of
shell deposits on the sea floor

serpentine = Mg3[(OH)4/Si2O3]
it belongs to the group of silicates

sandstone = mainly consists of quartz which is SiO2.
Sandstone actually is not a term for a specific content
of minerals but a term for the grain size the stone is
made of. Stones made of smaller grains are called
Siltstones, if the grain size is very small than you
have a claystone (hope this is correct translation from
german into english)

alabaster = CaSO4  * 2H2O :
It is the same as gypsum it is not calcium carbonate as
you say but calcium sulfate.

soapstone = Mg3[(OH)2/Si4O10]
It belongs - as serpentine - to the silicate group. It
is the same as talcum. I dont know if it is unhealthy to
breath the dust.

Hope you liked the info
cu
Christian