Sunday, 30 October 2011

Metamorphic rock ~ rocks and gems under pressure

Nephrite or greenstone
Metamorphic rock has been subjected to tremendous pressure and possibly heat as well, causing it to change in structure.  The rocks and gems included in the section below have all undergone a metamorphic process of some sort.

The piece of nephrite shown at the left is just such a rock.  It is known as greenstone or pounamu in New Zealand, the latter being its Maori name.  You can read more about it in the two articles linked to here:

1 comment:

Leigh Christina Russell said...

Hello PHR, with regard to your query about use and value, I've added links to the post above, to related articles about nephrite, jade and greenstone which give more information about those particular metamorphic rocks. As to value, that depends on what exactly you have and whether anyone wants to buy it. More precise identificaton may help you find answers to your question. Someone at a local rock hound club may know. There are many sorts of metamorphic rocks.
All the best,