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About Minerals

Birthstones of September

Sapphire

Sapphire is chemically and structurally the same as ruby—both are varieties oar the mineral corundum. Sapphires are well known as being blue—but can be nearly any color except shades of pink or red (since these are called rubies).

The blue color is by far the most popular color but orange/pink, golden, white , lavender, green and even black are seen.

Oriented rutile crystals cause a six pointed star light effect (asterism) to form the Star Sapphire. Sapphires are well known from places as Sri Lanka and India, and excellent specimens are also found in Tanzania, and the Kola Peninsula of Russia. Also they are found in many places such as North Carolina, Montana, Brazil, and China.

Sapphires are very durable (only diamond and moisannite are harder). Man Made sapphire crystals are used as the crystal faces in genuine Rolex watches and they are extremely scratch resistant.

Lapis Lazuli

Lazurite is a popular and expensive mineral, most commonly found combined with other minerals into a rock called lapis lazuli. Lapis is mostly lazurite, but commonly pyrite and calcite with other minerals. The name means "blue rock" and it is always s brilliant blue with violet or greenish tints. The rich blue color is due to sulfur that is inherent in the structure of lazurite. Small crystals of pyrite are always present in lapis and their brassy yellow color is both attractive and distinguishes lapis from its blue cousin—sodalite which lacks pyrite. The white streaks are from calcite, and too much affects the value of lapis.

Lapis lazuli has been mined for centuries from a locality in the remote mountain valley called Kokcha, Afghanistan. Beginning 6 centuries ago, the rock was taken to Egypt and present day Iraq, and later to Europe where it was used in jewelry ands for ornamental stone. Europeans also ground down the rock into a powder which was used as a pigment for paint. Today it is manufactured artificially.

Lazurite is a member of the feldspathoid group of minerals, which are minerals whose chemistries are close to that of the alkali feldspars but lack silica. They are found in silica poor rocks containing other silica poor rocks and no quartz. If quartz were present when the melt was crystallizing, it would react with any feldspathoids and form a feldspar. Localities that have feldspathoids are rare.

The name lazurite is often confused with the bright blue phosphate mineral lazulite. However the two minerals cannot be confused with each other because of lazulites vitreous luster and good crystal habit. The carbonate mineral azurite has a very similar color to lazurite but is associated with the green carbonate mineral malachite and reacts to acids.

As an aside - - The ancient Persians believed that the earth rested on a giant sapphire and its reflection colored the sky.