The gram price ranges from several yuan to several hundred yuan, even thousands of yuan.
Turquoise is one of the "Four Famous Jade" in China. It is named after its shape like a pine cone and its color is close to pine green.
Turquoise is a kind of water and copper-aluminum phosphate minerals, which belongs to phosphate minerals. Generally, it is generated by water flow precipitation. Turquoise is mainly opaque blue, but also light blue, turquoise, green, light green, yellow-green, gray-green and light color. Among them, the blue one is the most valuable and can be used as expensive jewelry decoration. Turquoise with pure colors such as blue, turquoise and green has a compact structure and can be used as a material for advanced art carving.
Generally, Mohs hardness is 5~6, specific gravity is 2.6~2.9, and refractive index is about 1.62. Under long-wave ultraviolet irradiation, it can emit light green to blue fluorescence.
Turquoise has uneven texture and different shades of color, and some even contain light stripes, spots or brown-black iron wires. The density also varies greatly. The texture with more pores is loose, and the density with less pores is hard.
Turquoise has a soft waxy luster to semi-glass luster after polishing. After polishing, fine turquoise looks like glazed porcelain, so it is also called "porcelain turquoise".
As a gem, it also has shortcomings. It is easy to fade and be corroded by strong acid when heated. The lower the hardness, the more pores, the stronger the water absorption and the more fragile it is. So sweat stains, stains, oil stains, rust, tea, cosmetics and so on. It may enter the gem along the pores, resulting in discoloration that is difficult to remove.
Since 2007, the price of turquoise has been rising all the way, even six or seven times. The price of turquoise with general quality is less than tens of yuan per gram, while the price of sky blue porcelain pine with high quality and good appearance is several hundred yuan or even thousands of yuan.