Polymorphs of silicon dioxide
More commonly known SiO2 gemstones
- Common Quartz
- amorphous forms (properties similar to: chalcedon, opal, obsidian, ...)
mechanosynthesis would allow for synthesis of pseudo amorphous configurations
Neo-polymorphs
Especially interesting since unusually hard and dense
- Stishovite Mohs 8.5-9.0 tetragonal –– may be transitionable into other gemstomes with the same rutile structure forming pseudo phase diagrams
- Seifertite Mohs ~9 orthorhombic –– (scrutinyte structure)
Both are metastable very hard and very dense.
They may not be very resilient against high temperatures.
Other polymorphs of SiO2
- (wiki-TODO: add some more known ones)
- https://en.wikipedia.org/wiki/Category:Silica_polymorphs
Basic low density polymprphs:
- https://en.wikipedia.org/wiki/Keatite Mohs 5.75 tetragonal
- https://en.wikipedia.org/wiki/Tridymite Mohs 7 orthorhombic (high temp modification)
- https://en.wikipedia.org/wiki/Cristobalite Mohs 6-7 tetragonal
(& high temp β-cristobalite cubic - diamond like structure) - https://en.wikipedia.org/wiki/Melanophlogite Mohs 6.5-7.0 cubic or tetragonal
- https://en.wikipedia.org/wiki/Coesite Mohs 7.7-8.0 monoclinic
Exotic stuff:
- https://en.wikipedia.org/wiki/Chibaite Mohs 7 cubic structure chalrate:
- https://en.wikipedia.org/wiki/2D_silica