Identification of authenticity of opal: Opal is generally protein color. If other atoms are doped, various colors can be formed, such as iron, calcium, magnesium and copper. Opal generally has a glass luster or a waxy luster. If the color and luster change with the angle, it is a precious gem, otherwise it is just a decorative stone.

Identification of fluorite authenticity;

A. zoom in and check the gap.

B. hot needle test of fusible resins and plastics.

C. Ultraviolet fluorescence observation shows that filled plastics and resins can produce characteristic fluorescence.

To sum up, it needs to be combined with professional knowledge to accurately identify. If it is not professional knowledge, it is recommended to go to the gold and silver jewelry testing center for certificate identification.