Sunstone and spectrolite often have shiller. A signet ring is a ring that was used as a means of identification for relatively important people. Some signet rings also had intaglio -carved seals . The earliest-known signet rings date from ancient Egypt, thousands of years ago. Pure silver has a hardness of 2.5.
Silver often occurs near copper lodes.
Silver 800 is used for casting. This glassy, lustrous mineral is found in lava flows, and obsidian stones can be massive. Most obsidian is 70 percent silica. Obsidian has a hardness of 5 and a specific gravity of 2.35. It is used for carvings and jewelry.