Sapphire jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of very special-purpose solid-state electronics (especially integrated circuits and GaN-based LEDs). Sapphire is the birthstone for September and the gem of the 45th anniversary.
Birthstone while the Gemological Institute of America starts it in Germany in the 1560s. Modern lists of birthstones have little to do with either the breastplate or the Foundation Stones of Christianity. Tastes, customs and confusing translations have distanced them from their historical origins, with one author calling the 1912 Kansas list (see below) "nothing but a piece of unfounded salesmanship." Ancient traditional birthstones are society-based birthstones. The table below contains many stones which are popular choices, often reflecting Polish tradition. There are poems which match each month of the Gregorian calendar with a birthstone. These are traditional stones of English-speaking