Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
This is a beryl of a different color. At first I thought this was tourmaline, as I have never seen an emerald in this color. Nope, RI indicates beryl. No chromium absorption. Have y'all ever seen a green beryl this color? If so, from where?
Joined: Fri Feb 24, 2006 1:20 am Posts: 2756 Location: Southern California, U.S.A.
The Zambian vanadium emeralds on the market years ago were incredibly clean -- to the point many dealers thought they were synthetic. They had a dark, somewhat "sinister" hue compared with Colombian goods but were eventually accepted by the market. I thought of them immediately when I saw the image but the stone looked almost too included
Joined: Fri Feb 24, 2006 1:20 am Posts: 2756 Location: Southern California, U.S.A.
Barbra Voltaire wrote:
Anyone know the area of Zambia or the specific mine which produced this material? Conditions of crystallization?
Emeralds are found exclusively in the Ndola Rural area of the southern Copperbelt where they are hosted by Muva-age talc schists intruded by tourmaline-and phlogopite-bearing pegmatite bodies, according to a Zambian resources website.
Since I was curious myself I noodled around a bit and found this site which gives fairly detailed geological info and mining history http://emeraldmine.tripod.com/ndola.htm
According to published info Zambian vanadium emerald made a big splash around 1976 and became a specialty of Israeli cutters who fashioned the ultra-clean material into shapes and brilliant makes previously not seen in emerald. At first the market resisted it but eventually manufacturers started using it and big retailers like Tiffany embraced it. Now it appears to be scarce again, replaced by more conventionally-hued Zambian stones colored by both vanadium and chromium mined by Gemfields.
Joined: Wed Jan 23, 2013 5:29 pm Posts: 1047 Location: Paris
I have seen beryls of that kind of colour in Madagascar. Like you, although the seller sold it as emerald, I first thought it was tourmaline ; but then all the specs said beryl. They have very strange, strong-coloured beryls in Madagascar, blue or green. I have a very unusual dark blue one, which I brought back from there.
Joined: Wed Jan 23, 2013 5:29 pm Posts: 1047 Location: Paris
OK I promise, you'll get it within a few days... Time for me to make different tries under different lights with my small tourist-camera. I am a very poor picture taker !
Joined: Wed Jan 23, 2013 5:29 pm Posts: 1047 Location: Paris
OK so here it is. The best I could do (background is supposed to be white !...)
10,99 carats. Concave cut. Normally not my favourite, but in this case it does nicely enlighten the stone.
As you can see the colour is not a pure blue, but contains a greenish tinge. When I bought it I was told this kind of stone is supposed to be heated to remove the green undertone and leave only a dark, deep blue aquamarine, which would be much more valuable. But this stone is too much included with liquid elongated and two-phase inclusions, and wouldn't have stood the heating, or it wouldn't have been worth it. Anyway this is the native untreated colour.
Dichroism is impressive, colourless/dark greenish blue.
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