The crystal is also called crystal. It is made of leaded glass or rare earth glass. It has no impurities and good transparency. Natural crystals are formed under natural conditions. Natural crystals come from nature and do not need to be processed. They are called aura stones. The outer surface is uneven, with fine lines inside and plants. It is the crystal closest to nature. In the ideal environment of artificial control, that is, the physical and chemical conditions meet the above conditions, the growth rate of crystal is about 0.8 mm per day (mm), which is also the standard production speed of many artificial crystal laboratories and factories. The crystal thus cultivated is the so-called "Synthetic Quartz", also known as "Cultivated Quartz" (CulturedQuartz). Artificial crystals are often cut into chips for use in the electronics, computer, and communications industries. The artificial crystal for general industrial use has a thickness of about 3 cm and takes about 40 days to grow. If it is to be used as a crystal ball for grinding 10 cm (100 mm) or more in the jewelry industry, in the most ideal environment. It usually takes about 120 to 180 days. In nature, the situation is not so optimistic, the conditions of raw materials, water quality, temperature, pressure, etc. have been changing, it is difficult to achieve the ideal situation, usually tens of thousands of times, or millions of times, in order to achieve the same growth . This is also why the “geological age†is calculated based on “millions of years†and is also the precious part of “natural crystalâ€. Wireless T-Shirt Bra Set,Bra And Panty Set,Soft Cup Bra Set,Wireless Mould Cup Bralette Set Guangzhou Charm May Apparel Co.,Ltd. , https://www.cmintimates.com