It is important to distinguish between a mineral and a mineraloid. A mineral is an inorganic, naturally occurring substance that has a characteristic chemical composition, distinctive physical properties, and solid crystalline structure (an order 3 dimensional arrangement of atoms or molecules). If it does not have this solid crystalline structure, it is not a true mineral and is therefore a "mineraloid."
No, it's a type of silica, and is classed as a mineraloid.
Opals are not truly minerals (because they don't have a crystalline structure), they are in a class called mineraloid. A mineraloid is an amophous, inorganics substance that lacks a crystalline structure, but are mineral in nature. You will find that in many older reference systems, they may well be classed as minerals.
Mineraloids are a mineral like substance that don't exhibit crystallinity. 5 Examples: mercury pearl obsidian anthracite jet
A mineraloid is a mineral-like substance that does not demonstrate crystallinity. Mineraloids possess chemical compositions that vary beyond the generally accepted ranges for specific minerals.
About 2700 kilometers
A mineraloid is a mineral like substance that does not dumonstate crystallinity
Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. A mineraloid is a mineral-like substance that does not demonstrate crystallinity.Now you get it?
nothing
they are obsidian, opal, limonite
No, it's a type of silica, and is classed as a mineraloid.
There really isnt a crystal form. Therefore it is a mineraloid.
Neither. Opal is a mineraloid, as it does not have a sufficiently organized structure to be considered a mineral.
No. A tektite is a drop of molten material (a glass) that is formed from the splatter caused when a meteorite hits the earth.
Opals are not truly minerals (because they don't have a crystalline structure), they are in a class called mineraloid. A mineraloid is an amophous, inorganics substance that lacks a crystalline structure, but are mineral in nature. You will find that in many older reference systems, they may well be classed as minerals.
An opal is considered to be a mineraloid, meaning that it has all of the properties of a mineral-- solid, inorganic, naturally forming, has a chemical composition-- but does not demonstrate crystallinity. Other examples of mineraloids include obsidian, an amorphous glass (that is not a crystal).
Opal is amorphous mineraloid, occurrence : Sedimentary and secondary from the alteration of high silica igneous extrusive rocks
It is apparently a mineral but because of it's liquid state it is considered a mineraloid. Minerals are suppose to have a crystal structure which mercury does not have and therefore is classified as a mineraloid.