Opal is "golden emerald with cat's eye effect". Also known as "cat's eye" and "oriental cat's eye", it is a rare and precious variety in jewelry, also known as Alexander's cat's eye, which has both discoloration and cat's eye phenomenon. Opal is one of the rarest and most precious emeralds. Only Sri Lanka is produced in the world, and the price is quite expensive. /kloc-It's hard to see domestic shopping malls above 0/0 carat. Crystal morphology is often short columnar or plate-shaped. -Quoted from Baidu Encyclopedia

Opal has special physical properties and can change its brightness with the color change of external light. This optical effect is called "cat's eye effect", which is the most precious wealth and natural gem given by nature to mankind. This variety of light and shade has become the most competitive feature of opal, which is a high-grade product in jade. It takes the right time, the right place and some luck to get opal.

Opals are often called "noble gems". Opals found at present are extremely rare, and there are almost no domestically produced gems, most of which come from Sri Lanka and Brazil. Of course, there will be fakes for such expensive items. Now with such advanced scientific and technological means, there are already artificial products.

A real opal can see a clear brown cat's eye. Especially in dark places, other gems absolutely have no such effect. Artificial opal is basically made of glass, with 2-3 bright bands at the top of the arc, but there is only one natural opal, which is the most obvious feature to distinguish between true and false. Of course, the safest way is to identify the true and false parts.