Opal is also called Shanshanyun, Opal, and Opal. It is a natural hardened silica gel containing 5-10% moisture. Opal is different from most gemstones in that it is amorphous. Opal belongs to the opal category in mineralogy. It includes two types of gemstones: color-changing and non-coloring. It is a kind of water-containing amorphous silica.
This is Australian opal, a by-product of opal ore. It was originally used for gardening decoration. It is very cheap, only a few cents each, and is polished into an egg shape. In the early years, they were sold in piles and boxes in antique streets or flower and bird markets. Later, as more people started playing with stones, the price started to rise dramatically. But after all, the output is there, the bubble has burst, and rationality has returned, and now it only costs more than a dozen yuan a piece.