When I was travelling around Ghana buying beads I came across some traders from Mali who had the most amazing collections of old Amazonite beads.The prices for these strands was a bit more than I had to spend so in the end I didn't buy any but I could kick myself now as the ones I have seen online are so lovely I would love to have them.
Amazonite is a type of green felspar.
"Also known as "green feldspar", these amazonite beads are some of the oldest and rarest beads we carry. Because of it's greatly admired and sought after blue/green tones, Egyptians used this stone for thousands of years, as did many tribal African peoples. Most of these beads were re-discovered in Mauritanian and Malian digs but have also been found in India and Egypt. A very conservative estimate of age for these beads is 2,000 years old, but amazonite beads have been known to be dated at 4,000 B.C. or older in Indian digs where the beads were visually identical to beads found in Africa"
http://www.africajohns.com/ancient for a good selection of stone beads -in the US but does world wide shipping
a short strand of dark and light amazonite beads
A very blue strand of amazonites from African trade beads