In Opals...
Where Silicon is Found
Pure silicon cannot be found in nature, though it makes up approximately 25.3-28.0% of the earth's crust, making it second in abundance (oxygen is first). Silicon is obtained by heating silica, or silicon dioxide with carbon or magnesium (or some reducing agent) in an electric furnace. It is also present in stars and the main part of a certain group of meteorites called aerolites. Silicon oxide is found in sand, rock crystals, quartz, amethyst, flint, agate, opal, and jasper. Granite, hornblende, feldspar, asbestos, mica, and clay all have silicate minerals in them.
Found at the beach... In Opals...
In Amethyst Gemstones...
In Agates...