Кварц – самый распространенный минерал в земной коре.. Chalcedony is also quite common in the strata. It often coexists with many different minerals. Поэтому, chalcedony gems often appear in front of the world in different appearances. Some special chalcedony is a masterpiece of nature, и это любимец коллекционеров. Потому что халцедон [...]
