This ring features raw Lake County Diamonds in bright sterling silver, it can also be made in black sterling silver, or 14k white or yellow gold. Current size is 9 US Can be resized between 3 to 9 Stone measurements: California - Lake County Diamonds are highly prized volcanic Quartz Crystals nicknamed similarly to Herkimer Diamonds, they are pressurized volcanic crystals that were formed hundreds of thousands of years ago when our volcano last erupted. Science has its own explanation for these wonders of nature. Lake County has been the scene of incredible volcanic activity throughout its ancient past. Mount Konocti, the area's defining landmark, is a dormant volcano where past lava flows of magma and basalt were contained under enormous pressure with temperatures of not less than 1,112 Fahrenheit. Heat and pressure resulted in the formation of beta silicon dioxide crystals - Lake County Diamonds -, Quartz of unsurpassed clarity and the finest optical quality. Lake County Diamonds are mostly clear and very hard, ranking from 7.5 to 8 (and possibly as high as 9) on the Mohs Scale, and like all diamonds, they can cut glass. They have been used commercially and industrially, but are in greatest demand as semi-precious gems. Lake County Diamonds may be set uncut for a rough natural look, or faced to set off their inner fire which compares in brilliance to African carbon diamonds.