Remember the "Sea of ​​Hearts" worn by the heroine Rose of Kate Winslet in "Titanic"? The prototype of the huge blue gem is the famous Blue Diamond. But in the movie, "The Heart of the Sea" uses a substitute that was still unknown in the past - Tanzanite. Tanzanite, the mineralogical name of the zoisite, was first discovered in Tanzania in 1967 and was named after it. In recent years, as the price of sapphire has risen again and again, the beautiful tanzanite has risen rapidly and has gradually become a new darling. The blue with a slight purple tone gives the gem an unusual charm. Tanzanite is produced at the foot of Mount Kilimanjaro in Tanzania, Africa, and there is only tanzanite produced in the world. Its color is usually greenish blue with brown tone, and gray, brown, yellow, green, light pink and so on. After heat treatment, it is blue or blue-violet, and most of the tanzanite is heat treated to improve color. Transparent, glassy. Its refractive index is 1.691-1.700, the density is about 3.35, and the Mohs hardness is 6-7. Unlike many gemstones, tanzanite has a strong trichromaticity, but the tanzanite after heat treatment shows only dichroism. As a property of tanzanite, pleochroism has become one of the important identification criteria for tanzanite. In China, Tanzanite is still far less famous than sapphire, but in many western countries, tanzanite has already become a high-grade gemstone. To date, the larger market for tanzanite is still in North America, and 80% of Tanzanite's annual production is sold to the United States. When people learned that the "heart of the sea" in the Titanic was tanzanite, it set off a wave of buying tanzanite. Today, the price of tanzanite in the United States has gradually approached sapphire. Although tanzanite is not very popular in China, it is more and more popular because of its lower price than sapphire and color comparable to sapphire. In the past one or two years, the increase has been enormous. About 50%. For investment collectors, tanzanite, which is sparsely produced, is a concern. Yangzhou Lansun Slipper Co.,Ltd , https://www.lansunslippers.com
