Amazonite Jewelry

Where the name comes from: The Amazon River, though no stones have been found in the region, it may be a reference to the green coloration.
Where the stones come from: Infrequent localized occurrences, Colorado, Russia, Brazil, Madagascar.
Chemistry: Potassium aluminium silicate, KAlSi₃O₈ - a green variety of feldspar,
Colors: Green to blue-green to yellow-green, the color comes from the inclusion of lead, water and possibly iron.
...and another thing: Heating above 300C will lose the color.
 

Prices correct at time of writing - subject to change