A lot of jewelry with stones of exotic names appeared on the market. One of those is Tanzanite, which is a kind of Zoisite. It is a mineral discovered in 1967 by Indian precious-stone seeker Manuel de Souza in Tanzania, in the region of mountain Kilimanjaro. Its commercial name was given by jewelry company Tiffany & Co from New York, and promoted by American actress Elizabeth Taylor.
Tanzanite is valued for its violet-blue color and at the beginning was even confused with a Sapphire. Nowadays clients face a dilemma – Tanzanite or Sapphire?
It is true, that every precious stone of good quality will reach high price – regardless of its name. Therefore, jewelry shops use low quality stones basing on unawareness of clients. In such a case it’s difficult to judge unequivocally which stone is worth more. However, few buyers know Sapphire has one, fundamental advantage over Tanzanite. In so called Mohs scale (from 1-10, hardness 10 is a diamond, and 1 – talc) Tanzanite is between 6 and 7. What does it mean in practice?
With certainty all of us heard such an expression as sapphire glass. It is simply synthetic sapphire which is cut to have the proper size and thereafter set in e.g. watches. Both natural and synthetic sapphire have hardness 9. Therefore it is much harder than Tanzanite, which can be compared to mineral glass. On daily use it is much easier to scratch mineral glass, what I have discovered when I bought a very nice watch that nowadays can be only worn to my workshop, because the glass is so heavily scratched. My next watch had sapphire glass, which can only be scratched by another sapphire or a diamond (the hardest in a scale) and till today the glass surface is flawless.
How does it apply to jewelry? If we are buying product that will serve us for many years or even for generations, it is worth to invest in the most durable material, that will be long-lasting. Sapphire is one of them. However, if you decide on Tanzanite, it’s worth to pay attention to its proper protection. More prongs in a setting, which is also a little bit lower, causing restricted access to the stone so it will be more difficult to scratch it.