Iolite is made up of magnesium, aluminum, and silicon (chemically, it's known as magnesium aluminum silicate) and also sometimes has iron. Iolite rates a 7 to 7.5 on Mohs Scale, making it a tough stone, but the sources I read, including AGTA, cautioned to keep iolite gems away from high-traffic zones where it could get bumped or hits. This advice means iolite would be best for pendants and earrings, and not a good choice for bracelets or rings.
Iolite is found in several locations, including Brazil, Burma, India, Sri Lanka, and Africa. There is also a large deposit of iolite in Wyoming, discovered by Dan Hausel, a geologist at the University of Wyoming. He estimates that that area may contain over a trillion carats of iolite, in addition the gemstones he's already uncovered, weighing over 24,000 carats each - wow! According to Hausel, this may make Wyoming home to the largest colored-gem deposit in the world.
Connie Drake wrapped these delicate iolite briolette beads into pendants with 22-gauge gold filled wire.