4mm Blue Sapphire Earrings in 14 Karat Gold cb4dd9096afc563d5d1b89ac6b2d535b Opal is composed of hydrated

Opal is composed of hydrated silica

similarly to agate

It is used in industrial settings

Zircons are relatively inclusion free

4mm Blue Sapphire Earrings in 14 Karat Gold cb4dd9096afc563d5d1b89ac6b2d535b Opal is composed of hydratedThe word sapphire comes from the Greek translation for blue and was used in ancient times to describe any blue stone, often lapis lazuli. Around 1800 it was discovered that sapphires are a gem variety of corundum, the other being ruby. Corundum is a hard stone, rating a 9 on the Mohs scale, making it the second hardest natural mineral. Its chemical composition is aluminum oxide. The many colors in which corundum occurs are due to the presence of other