<p>Soapstone, undetermined age, undetermined provenance.  This sample is a pyritic soapstone - the small, dark-colored patches are pyrite crystals.  The light-colored, curvilinear structures are veins.
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This is the oddest decorative stone lithology.  Soapstone is a talcose, generally crystalline-textured, metamorphic rock.  Most soapstones form by metamorphic alteration of serpentinites.  Being composed of talc, this rock has a hardness of 1 on the Mohs Hardness Scale, and is easily scratched.  So I wonder what good is it as a decorative stone? (I honestly don’t know.)
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/jsjgeology/33862267441/">Soapstone 3</a>