Mineralogy

Epitaxy refers to the deposition of a crystalline overlayer on a crystalline substrate.

Gemology or gemmology is the science dealing with natural and artificial gemstone materials.

A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

Geode (Greek γεώδης - ge-ōdēs, "earthlike") are geological secondary structures which occur in certain sedimentary and volcanic rocks.

A solid solution is a solid-state solution of one or more solutes in a solvent.

Crystallization is the (natural or artificial) process where a solid forms where the atoms or molecules are highly organized in a structure known as a crystal.

Fulgurites (from the Latin fulgur, meaning "lightning") are classified generically as a variety of the mineraloid lechatelierite, although their absolute chemical composition is dependent on the physical and chemical properties of target material affected by the discharge of cloud-ground lightning.

Moon rock or lunar rock is rock that is found on the Earth's moon, or lunar material collected during the course of human exploration of the Moon.

The chlorites are a group of phyllosilicate minerals.

A xenomorph (also: allotriomorph) is a mineral that did not develop its otherwise typical external crystal form because of late crystallization between earlier formed crystals.

A crystal is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions.

Plumosite is a questionable mineral.

Bristol Diamonds are not actually diamonds but quartz crystals found in geodes, geological rock formations which occur in dolomitic conglomerate found in the Avon Gorge in Bristol, England.