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What is this gemstone?

I have 2 gems which are dark and how a high bright vitreous lustre. When illuminated with a torch they display a red colour underneath

RI- cant see RI Reading
SG- 4.19 for both gems
And can’t do other test due to them being opaque

Das könnten Almandin Granate sein. Ich habe in Tansania auch solche Exemplare gefunden.

1 Like

You might find this IGS Specific Gravity Index helpful.


I agree with the other poster who thinks this is almandite/pyrope garnet. The surface appearance is right for this species and the color and SG are, too. It is pretty typical for run of the mill red garnet like this to be rather dark in larger pieces. If it were cut into small stones of 1ct or less, it would likely be dark red, but not opaque. However, this type of garnet is very common, so it isn’t really worth spending the money to have it cut. There are varieties of almandine/pyrope and related species which are lighter red, pink, peach, etc., and these are increasingly popular and in demand and come in some very pretty colors. The place that these came from probably only produces this color, but you could check to see if there are lighter pieces.