OVERVIEW

allan June 1, 2017 No Comments

OVERVIEW

OVERVIEW

ABOUT TANZANITE

Found in just one place on earth, tanzanite is a relatively recent discovery. Tiffany & Co named this blue-violet variety of zoisite in honor of Tanzania, where it was first unearthed in 1967. Because the crystals show different colors depending on the viewing direction, cutters can fashion gems with a range of color from violetish blue to bluish violet depending on how much weight they want to retain from the rough.


BIRTHSTONES & ANNIVERSARIES

Tanzanite is a birthstone for December, along with zircon, turquoise, and blue topaz. Tanzanite is also the gem for a 24th anniversary.

MERELANI

Tanzanite has only one source: the hills of Merelani in northern Tanzania.


1967

Masai tribesman Ali Juuyawatu is credited with finding the first tanzanite crystal.


PLEOCHROIC

Tilt tanzanite and you’ll see three distinct colors in three crystal directions.


FACTS

  • Mineral: Zoisite
  • Chemistry: Ca2Al3(SiO4)3(OH)
  • Color: Violet blue to bluish violet to violet purple
  • Refractive Index: 1.691 to 1.700
  • Birefringence: 0.008 to 0.013
  • Specific Gravity: 3.35
  • Mohs Hardness: 6 to 7

TREATMENTS

There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.


SYNTHETICS

Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.


IMITATIONS

Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.

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