Birthstone for June. Hardness 2.5 - 4.5. A durable stone with a hardness of 6.5 - 7. Ovals in 3x4mm, 3x5, 4x5, 4x6, 7x5mm. Pears in 3x4mm, 4x5, 4x6mm.
Opals come in all colors.
Birthstone for October. Hardness is 5.5 - 6.5. Hardness is 9. Tanzanite should be mounted in a protective setting. Hardness is 6 - 6.5.