RARE Wampum (quahog shell) Navajo Handmade Teardrop Pendants.  These measure 1 5/8" tall and the stone is 19mm wide.  All sterling silver.  Last photo shows other earrings also available.

Wampum was officially recognized as a currency by Massachusetts Bay Colony on October 18, 1650 ... strings of eight, 24, 96 and 480 beads has currency values for trading. Also known as quahog shell, a clam with purple and white coloring. Wampum Quahogs shells are found in the waters from Cape Cod south to New York, with a great abundance in Long Island Sound. Usually only available up in the northeast US, recently bead manufactures have been cutting them into beads for jewelry making.