الكوارتز هو المعدن الأكثر وفرة في القشرة الأرضية. Chalcedony is also quite common in the strata. It often coexists with many different minerals. لذلك, chalcedony gems often appear in front of the world in different appearances. Some special chalcedony is a masterpiece of nature, and it is the favorite of collectors. Because chalcedony [...]
