Friday, April 15, 2011

Ametrine

Ametrine is a bi-colored quartz: part amethyst and part citrine. It occurs in eastern Bolivia near the border with Brazil.



Typically, gem cutters aim for a well balanced color split and show it off with a rectangular step cut.



I am unsure of the particulars of how the coloring occurs naturally, but this is how it looks:



This distinctive color zoning, in the hands of an imaginative gem cutter, can yield striking stones.



Ametrine can be produced through careful heating of amethyst, as well. Heat changes the purple to yellow.

In 1994, a Russian lab perfected the synthesis of bi-color quartz, so beware of high quality goods at low prices or sold as Russian in origin.



This is a beautiful example of synthetic quartz. Note the seed plate in the center:



And to end on a happy note, I leave you with a particularly artful example of unconventional lapidary:

11 comments:

mcstoneworks said...

What a cool stone. Thanks for some great information regarding it. That last stone is unbelievable.

Koolbraider said...

What an incredibly beautiful stone! And another perfect example of purple combined with yellow/orange. Nature teaches us another color lesson once again.

Cat said...

That's a stone that has always fascinated me.
So beautiful!

Jeanne/J3Jewelry said...

I love ametrine, it's such an elegant stone. I'm curious what a "seed plate" is though.... what is it for and what does it do?

BeadSire said...

Very informative with great examples, its a lovely stone.

MmeMagpie said...

Jeanne: The seed plate is the thin slice of quartz in the center. This plate acts like a template for the growing crystal as it forms in the autoclave.

Sometime back i did a post on synthetic quartz. I'll see if I can find it.

MmeMagpie said...

Here's that post on Synthetic quartz:

http://starvingartiststeam.blogspot.com/2010/08/synthetic-quartz.html

DawninCal said...

I wasn't aware of this Ametrine until reading today's blog post. It's stunning.

I agree with Koolbraider that it's amazing how nature figures out the perfect color combinations. It doesn't seem to matter if it's flowers, butterflies, birds, fish or stonre - the color combos are always perfect.

Bonnie said...

This is a fabulous stone. I enjoyed seeing a photo of the uncut stone. It certainly adds to my respect for cutters.

Erika Price said...

Great article and fabulous photos - ametrine is one of my faves!

Stacie @ azoho.com said...

Holy Schmoly- that last piece is AMAZING!!!!!