Quartz là khoáng chất phong phú nhất trong lớp vỏ trái đất. Chalcedony is also quite common in the strata. It often coexists with many different minerals. Vì thế, 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 […]
