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Anatase, a captivating yet uncommon gemstone, is prized by collectors for its unique properties. Here’s what sets it apart:

Not Your Everyday Gem:

  • While not widely used in jewelry, Anatase’s rarity and visual intrigue make it popular among collectors.
  • It can resemble blue sapphire, but with a distinct crystal structure.

Crystal Structure:

  • Anatase exhibits a tetragonal crystal form, often with slight variations.
  • Its rough crystals may show 4 clear faces, similar to some sapphires. However, sapphires have a trigonal bipyramidal structure with 6 clear faces.

Identifying Features:

  • Similar to other gemstones, Anatase may have striations (lines) running along its main axis and in opposite directions.
  • Triangular markings can also be seen on rough Anatase crystals.

Cut and Polish:

  • Anatase is more sought-after as rough crystals by collectors than as cut and polished gemstones.

Color Variations:

  • Beyond the sapphire-like blue, Anatase can also be found in green, purple, and brown hues.
  • Damaged Anatase crystals can also be found occasionally.

Associated Minerals:

  • Anatase can be well-developed alongside other gems and minerals like quartz and apatite.

Chemical Composition:

  • Classified as a titanium dioxide (TiO2) mineral, similar to rutile.
  • Titanium and oxygen are its main elements, with trace elements causing color variations.
  • Interestingly, brookite, anatase, and rutile share the same chemical formula (TiO2) but have distinct crystal structures.

Physical Properties:

  • Anatase can exhibit a double refractive index (2.534 & 2.564 or 2.488 & 2.497).
  • It has a high specific gravity (3.97) and a hardness of 6 on Mohs scale.
  • Dichroism (color change with viewing angle) can be observed, appearing as dark yellow/brown or green/blue.

Discovery and Origin:

  • First identified in 1801 by French mineralogist Renรฉ Just Haรผy.
  • Found in locations like California, Brazil, Italy, and Sri Lanka.

Remember: Anatase’s rarity, unique crystal forms, and color variations make it a fascinating gem for collectors, even though its use in everyday jewelry is limited.