Tanzanite

Tanzanite's gorgeous hue is its key selling point. Its hue varies between pure blue and purplish-blue. Due to its strong pleochroism, it will exhibit varying color saturation depending on the viewing angle. When faceting a Tanzanite gemstone, careful consideration must be given to which angle will produce the brighter blue hue rather than the more muted gray tone. This gemstone has flawless cleavage in one direction, thus caution must be used while faceting to avoid chipping. The same goes for Tanzanite jewelry, which should be worn delicately and avoided contact with rough surfaces.

Henry Platt, vice-president of renowned jewelry manufacturer Tiffany & Co., came up with the term Tanzanite in 1969. Tiffany made a significant effort to advertise this new gemstone under its new name, and Platt's efforts paid off as this gemstone quickly gained enormous popularity. The term Tanzanite gained popularity and is now widely used in the gem industry.

Tanzanite is a relatively soft for gemstone. This places somewhat of a limitation on its uses and care must be taken to protect it from being scratched. Tanzanite also has a low resistance to ultrasound and should not be cleaned with ultrasound cleaners as this may cause the gemstone crack. Although Tanzanite has a lovely color and appeal, it does have several limitations in its durability. 

Gemstones with tanzanite are always heated. Heat treatment exceeding 800 degrees Fahrenheit (or 430 degrees Celsius) transforms the drab gray, green, or brownish color of natural Tanzanites into a vivid blue to violet hue.

Tanzanite has a distinctive color because to its violet undertone. It closely resembles iolite, but may be identified due to its lower specific gravity and refractive index. Iolite often has a darker hue. Tanzanite is often more purple than blue Sapphire but lacks the deep purple tint of Amethyst. Although it could resemble various purple Sapphire colors, it can be identified by its significantly lower hardness.