Mineral Properties, Uses and Descriptions. WolframAlpha: Minerals. Mineralogy Database. National Geographic: Minerals, Gems Information. More than 4,000 naturally occurring minerals—inorganic solids that have a characteristic chemical composition and specific crystal structure—have been found on Earth.
They are formed of simple molecules or individual elements arranged in repeating chains, sheets, or three-dimensional arrays. Minerals are typically formed when molten rock, or magma, cools, or by separating out of mineral-rich water, such as that in underground caverns. Geology.com: Mineral Properties, Uses and Descriptions. Mineralogy4Kids.org. Geology.com: Rocks. Lapis Lazuli Lapis Lazuli - a metamorphic rock and the most popular blue opaque gemstone in history.
Tumbled Stones.