Natural glass (obsidian) is a volcanic rock, but it is not a ‘mineral’ because glass is not crystalline: it is a supercooled liquid: no crystals had time to form.
But ‘glass’ (no matter what it is made of) is never ‘a mineral’ because it is glass: a non-crystalline solid material.
Why volcanic glass is not considered a mineral?
Note also that the “minerals” as used in the nutritional sense are not minerals as defined geologically. Glass – can be naturally formed (volcanic glass called obsidian), is a solid, its chemical composition, however, is not always the same, and it does not have a crystalline structure. Thus, glass is not a mineral.
Why is charcoal not a mineral?
Charcoal is not a mineral. It is a solid material, that can look like a mineral or rock, but it is actually the ‘charred’ remains of wood. Wood is organic, so charcoal is not a mineral.
Are glass bottles a mineral?
Inorganic substance: yes. Definable chemical composition: SiO2 *Actually, most industrially-produced glass is not pure silica, but having impurities is still a definable chemical composition so this part of the definition is ok. Orderly arrangement of atoms in a lattice: NO. This is why glass is not truly a mineral.
Is glass a type of rock?
In nature, glasses are formed when sand and/or rocks, often high in silica, are heated to high temperatures and then cooled rapidly. The Glass in Nature display shows specimens of glass made in nature. Obsidian or volcanic glass, for example, is molten rock that has quickly cooled, becoming rock in a glassy state.