|Dimensions (mm)||not provided|
|Weight (carats)||not provided|
This is a natural untreated rough piece from Bolivia which is ready for cutting or keeping as a specimen.
Weight 71.40 cts app.
Size 28.7 x 21.5 x 19.7 mm app
We have cut some stones from this parcel which can be seen at our sister site
Ametrine, also known as trystine or by its trade name as bolivianite, is a naturally occurring variety of quartz . It is a mixture of amethyst and citrine with zones of purple and yellow or orange. Almost all commercially available ametrine is mined Bolivia although there are deposits being exploited in Brazil and India
The colour of the zones visible within ametrine is due to differing oxidation states iron within the crystal. The different oxidation states occur due to there being a temperature gradient across the crystal during its formation.
Artificial ametrine can be created by differential heat treatment of amethyst.
Most ametrine in the low price segment can surely be assumed to stem from synthetic material. Since 1994 a Russian laboratory has perfected the industrial production of bicolored quartz crystals that are later irradiated to bring out the typical ametrine colors. Green-yellow or golden-blue ametrine does not exist naturally.
Very pretty royal blue lapis.Arrived today from Australia to USA. Was shipped 8/3 here on 8/14. Price and registered mail cost all reasonable. Smooth transaction. I'll buy more soon.61.63 CTS LAPIS LAZULI ROUGH-AFGHANISTAN F4384
|Starts||13th Aug 2017 8:02pm PDT|
|Ends||16th Aug 2017 8:00pm PDT|
|Registered Shipping||$15.00||10 Days|
|Standard Shipping||$4.00||21 Days|
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