What Is a Linde Star Sapphire?

A Linde star sapphire is a synthetic gemstone that exhibits asterism. Its inventor created it by accident, while trying to make synthetic sapphires with consistent color.

Definitions

A star sapphire is a gemstone composed of corundum, aluminum oxide, which displays asterism. This phenomenon arises from the presence in the gemstone of tiny strands of minerals that capture and reflect light in a star pattern. The star, which appears to move around as the position of the sapphire changes, usually has six rays, but 12-ray stars also sometimes occur. Star sapphires come in several colors, including blue, rose, smoky brown and translucent, which is especially prized.
Linde star sapphires are synthetic gemstones that also exhibit asterism. Like the natural stones, they come in a variety of colors, though the stars in them do not move. Since their accidental creation, they have become very popular in gemstone jewelry.

Creation

The Brazilian Connection, an online retailer of gemstones and gemstone jewelry, conducted an interview with Jack Burdick, an inventor who worked for Linde Air Products Co. In 1947, Burdick and his colleagues were trying to create synthetic sapphires with consistent color throughout, a goal that had eluded chemists for decades. In the laboratory, Burdick and his team created sapphires with only titania in them. They heated the resulting gems for several days and then took them out of the furnace, only to learn that they were milky rather than clear.

A Eureka Moment

Quite by accident, Burdick took one of the sapphires outside. He noticed when he looked at the stone in sunlight that it had a star in it. In the interview, Burdick described the discovery as a success achieved when the team was trying to accomplish something quite different.

Commercial Success

Linde Air Products patented its star sapphires in 1949 and commenced making them for jewelry. According to Burdick, the company sold $100,000 worth of the star sapphires in the first six months it offered them for sale.
The company discontinued star sapphire production in 1974 because of increasing competition from overseas manufacturers.

Linde Star Sapphire Jewelry

Linde star sapphires are nearly always cabochon-cut, with smooth, curved surfaces rather than facets. They most commonly appear in rings, earrings and pendants, usually with settings made from precious metals like gold and sterling silver. Linde star sapphires are considerably less expensive than natural stones.