bead identification

[grandma's necklace]

can someone give me ideas on how to identify the stone (bead) used in an old necklace i have inherited from my grandmother. It is on a sterling silver chain and has about 16 small beads strund along it ending in a large flat triangular stone. It is  light green with a marbling or mottled appearance with a one or two streaks through it. it is not translucent.
appreciate your help
grandma's necklace

[Polly]

Your best bet would be to take it to local rock shop.  You can usually find them under "Lapidary" in the yellow pages. Call before going in case they have odd hours. You'll often find the owner behind the counter, willing to share decades of rockhound knowledge.

Since it is patterned and not translucent, it is likely to be some type of jasper. You might find a match in our gemstone beads index, but I think you're better off showing it to someone in person.

--Polly