ABC Wednesday - X

ABC Wednesday has reached the difficult letter X.

After long thought (and some research) I've decided to offer
X
for
XENOLITH

The name xenolith comes from the Greek for "foreign rock". In strict geological terms it's a rock which has become embedded in a different type of rock while the latter was in a molten state (see this article) although the definition can be stretched to include a foreign fragment included in a sedimentary rock.
So I'm entitled to stretch a bit!

The series of photos below show a rough piece of slate (sedimentary rock) enclosing an almost spherical group of bright pyrite crystals.

I would certainly not want to use that slate on my roof - it's much too pretty!

ABC Wednesday was started by Mrs Nesbitt, and more participants can be found on the Anthology site or the Linky page.

A very good New Year to all of you.
May the best of the Old be the worst of the New.