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The Common Uses for Sapphires

Sapphires are corundum, a mineral most often mined from stream beds where they have settled, and used primarily for jewelry in different colors and shapes. Blue sapphire is the most common, but red sapphire is a ruby. Other colors may be from clear to pink to green and black. Chromium gives corundum a pink appearance, and more chromium makes it red, creating a ruby. Iron and titanium contamination creates the blue and green stones.

Jewelry
- Sapphire has been used for fine jewelry for centuries. Sapphire mines in the United States are located in Montana and North Carolina, but sapphires used for most jewelry manufacture come from Thailand, Sri Lanka and India. Adding titanium creates the special appearance of a star sapphire. The special optical appearance occurs when the titanium crystallizes in needle form. Jewelry stores have marketed synthetic star sapphire since 1947, Emporia University reports.
Grinding
- Sapphire registers a nine on the Mohs scale for hardness, and a diamond registers a 10. Because the stone is hard, grinding uses are common. Crushed corundum is ground to grit or powder for grinding media to make sandpaper, polishing compounds and cutting tools, according to Geology.com. Corundum was used as a grinding tool as many as 6000 years ago, reports the Harvard University Gazette.
Lasers
- Ruby was the first basis for a laser, and this Ti-sapphire laser wavelength is adjustable at the red-to-infrared region of the electromagnetic spectrum, according to the Reade website. NASA has used corundum and other gemstones to collect natural elements from the solar winds. The purity of gemstones like sapphires helps with detection of minute traces of elements, reports Slate.
  
  In an unusual twist, the use of the laser may determine if sapphires have been heat-treated, according to the Canadian Institute of Gemmology. The laser created from sapphires may be the best detector of the heat treatment of sapphires.
LED
- Light-emitting diodes, or LED, lighting uses a substrate or first layer of sapphire or corundum, creating the LED as an expensive alternative to other bulbs. This lighting uses less electricity than incandescent lighting and is safer than compact fluorescent bulbs that use mercury. Sapphire is an expensive component of the LED, but Purdue University has developed an alternative that may replace the expensive sapphire. Electronics and toys are common uses for LED lighting, but many uses could apply if economics would allow.

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