Based on the Moh’s scale of hardness, Tanzanite is 6.5 to 7 which means it is a slightly soft gemstone, similar to Emerald but less brittle, and therefore needs to be treated with care. Diamond is the hardest gemstone, scoring a 10 on the scale.
Do not use jewellery cleaner as the chemicals will be too harsh for the Tanzanite. Instead clean it gently with a soft toothbrush using warm soapy water and dry with a soft cloth. Avoid ultrasonic cleaning.
With just a single source and limited supply, it is believed that with the current mining rate, there remains approximately only 15 to 20 more years of Tanzanite in the ground. Ultimately, this indicates that beyond our present generation, the mining of Tanzanite will cease thus those purchasing today are the last first-time buyers of this precious gemstone.
Whether a Tanzanite is a blue or violet stone is determined by which axis the face of the stone is cut as you can see both colours when you turn the stone around. As it is the same stone there is no difference between the value of one over the other. It is purely down to personal preference.
It should be assumed that all Tanzanite purchases have been gently heated, with the exception of some stones that were found close to the surface in the early days of discovery. These stones were a gem-quality blue without the need for heat treatment as they had already naturally been exposed to heat in the likely form of volcanic activity or bush fires. Today’s gentle heating process is merely a continuation on what Mother Nature began.
Tanzanite is a variety of Zoisite of which the colour is caused by vanadium in the gem, that when cut and polished, becomes a dazzling kaleidoscope of royal blue, indigo and periwinkle. Gem Zoisite crystals with other minerals inside, say manganese, chrome or iron, cause the human eye to see other colours and these are referred to as Fancy Stones.
Fancy Stones are found in many colours and colour combinations as in green, pink, brown, yellow, violet/blue and violet green. This stone is extremely rare as they are only found sporadically in very small quantities, with pink being amongst the rarest and highly sought after by gem collectors.
New York’s celebrated Jewelers, Tiffany & Co, heard about the discovery in Tanzania and were the first to bring the dazzling new gemstone to the world. They christened the new find “tanzanite” after its’ country of origin, declaring it to be the most beautiful blue stone to be discovered in over 2000 years. They proudly stated that tanzanite could only be found in two places on earth, and that is in Tanzania and at Tiffany’s.
Selecting the color of your tanzanite is a matter of personal preference. The bluest hues are among the rarest, but tanzanite in all shades, from flattering lilac and cornflower blue to deep blue, indigo and violet, continue to enchant discerning jewelry buyers seeking exceptional beauty and distinction.
Like all precious gemstones, tanzanite should be treated with care to preserve its beauty and value. You can read more about this in our Tanzanite buying Guide. Ultrasonic cleaning and abrasive cleaning solutions should be avoided. Tanzanite should be cleaned using a small, soft brush and warm, slightly soapy water. Gently clean the upper and underside of the tanzanite, and dry carefully with a soft, clean cloth. Tanzanite should not be exposed to sudden extremes of temperature and should be stored in a protective pouch or box separately from other jewelry. When jewelry is being altered or repaired, the tanzanite should be removed from its setting beforehand.