Garnets are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives.
Garnet
A sample showing the deep red color garnet can exhibit.
Crystal structure of pyrope garnet. White spheres are oxygen; black, silicon; blue, aluminium; and red, magnesium.
Same view, with ion sizes reduced to better show all ions
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust.
Lithium aluminium silicate mineral spodumene
Diatomaceous earth, a biogenic form of silica as viewed under a microscope. The imaged region measures approximately 1.13 by 0.69 mm.
Nesosilicate specimens at the Museum of Geology in South Dakota
Kyanite crystals (unknown scale)