1 Talk Calcium carbonate Edit Fossil Record Calcium carbonate is a mineral. Small shelly fossils are commonly composed of calcium carbonate. This article is a stub. You can help Fossil Wiki by expanding it. Read more In geology, rock is a naturally occurring solid aggregate of minerals and/or mineraloids. Rock (geology) Silica is a mineral. Small shelly fossils are commonly composed of Silica. it is w still found today Silica Calcium phosphate is a mineral. Small shelly fossils are commonly composed of calcium phosphate. Calcium phosphate Related Categories Categories: Article stubs | Rocks Add category