Mined in Brazil, these are calibrated diamond cut Tourmaline gemstone beads, also known as micro cuts. The many facets give these yellow and green Tourmaline gemstones maximum sparkle. These micro cut Tourmaline beads measure 3mm. You will receive approximately 140 micro diamond cut Rainbow Tourmaline beads on a 15 1/2" strand. Surely, you could use some of these Tourmaline beauties in your stash.