White sapphire: Difference between revisions
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== Terminology == | |||
Advantages | "[[White sapphire]]" (meaning clear transparent colorless) because we want to focus on perfect crystals without any color giving impurities. <br> | ||
* very hard material (Mohs 9 – defining mineral), very high heat conductivity | A base material for [[gemstone metamaterial technology]] would be perfectly impurity free and colorless clear. <br> | ||
* made out of the extremely common element aluminum (more common than carbon) | |||
* thermodynamically stable not just metastable thus very heat resistant | Just "sapphire" usually refers to sapphires with impurities (iron and titanium ions replace aluminum ions) causing a blue to black color. <br> | ||
Also called '''lecosapphire or leukosapphire''' (may be more prevalent in German). | |||
* Crystal structure: trigonal | |||
== Advantages of this gem == | |||
Maybe look at metastable polymorphs at the eventual cost of somewhat less heat resistance? | * very hard material ('''Mohs 9''' – defining mineral), very high heat conductivity | ||
* made out of the '''extremely common element''' aluminum (more common than carbon in [[diamond]] or [[moissanite]]) <br><small>Possibly helpful on the [[Moon]] with carbon being scarce.</small> | |||
* like [[moissanite]] sapphire is '''thermodynamically stable''' not just metastable like [[diamond]] thus '''very heat resistant''' | |||
* Crystal structure: '''trigonal''' – Not as high symmetry as cubic but still '''good'''. | |||
Maybe look at metastable Al<sub>2</sub>O<sub>3</sub> polymorphs at the eventual cost of somewhat less heat resistance? | |||
== | == Isostructural gems ([[Hematite structure]]) == | ||
* [[Tistarite]] Ti<sub>2</sub>O<sub>3</sub> | |||
* [[Hematite]] Fe<sub>2</sub>O<sub>3</sub> | |||
See: [[Simple crystal structures of especial interest]] | |||
== Related == | == Related == | ||
* '''[[Deltalumite]]''' – a tetragonal polymorph of Al2O3 with spinel structure | |||
* '''Tistarite Ti<sub>2</sub>O<sub>3</sub> has the same structure.''' => [[neo-polymorph]] series? | * '''Tistarite Ti<sub>2</sub>O<sub>3</sub> has the same structure.''' => [[neo-polymorph]] series? | ||
* '''[[Gemstone like compounds with high potential]]''' – [[Gemstone like compounds]] | * '''[[Gemstone like compounds with high potential]]''' – [[Gemstone like compounds]] | ||
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* [[Diamond]] is much less heat and oxidation resistant. | * [[Diamond]] is much less heat and oxidation resistant. | ||
* Both [[diamond]] and [[moissanite]] have higher crystal structure symmetry than leukosapphire | * Both [[diamond]] and [[moissanite]] have higher crystal structure symmetry than leukosapphire | ||
---- | |||
* '''[[Base materials with high potential]]''' | |||
[[Category:Base materials with high potential]] | [[Category:Base materials with high potential]] | ||
[[Category:Gemstones with color based names]] | |||
== Polymorphs == | == Polymorphs == | ||
'''Deltalumite''' Al<sub>2</sub>O<sub>3</sub> (δ form of corundum, polymorph of [[sapphire]]) – tetragonal – Mohs ? – | '''[[Deltalumite]]''' Al<sub>2</sub>O<sub>3</sub> (δ form of corundum, polymorph of [[sapphire]]) – tetragonal – Mohs ? – | ||
== Trivia == | |||
* 🟥 '''Ruby is just red sapphire.''' Color from Chromium Cr. | |||
* | * 🟦 Classic blue is from elements (Fe,Ti) | ||
* | * ⬜️ transparent, no impurities, white sapphire | ||
* | * 🟨 There are many other possible colors from impurities/dopants. | ||
---- | |||
* 🟢 '''Emerald is NOT a form of sapphire but a green form of [[Beryl]].''' <br>a beryllium aluminum silicate harder than typical silicates. <br> [[Beryllium]] is a quite rare element so forms of beryl are not that viable as a structural material. | |||
== External links == | == External links == | ||
Latest revision as of 08:32, 23 September 2025
Terminology
"White sapphire" (meaning clear transparent colorless) because we want to focus on perfect crystals without any color giving impurities.
A base material for gemstone metamaterial technology would be perfectly impurity free and colorless clear.
Just "sapphire" usually refers to sapphires with impurities (iron and titanium ions replace aluminum ions) causing a blue to black color.
Also called lecosapphire or leukosapphire (may be more prevalent in German).
Advantages of this gem
- very hard material (Mohs 9 – defining mineral), very high heat conductivity
- made out of the extremely common element aluminum (more common than carbon in diamond or moissanite)
Possibly helpful on the Moon with carbon being scarce. - like moissanite sapphire is thermodynamically stable not just metastable like diamond thus very heat resistant
- Crystal structure: trigonal – Not as high symmetry as cubic but still good.
Maybe look at metastable Al2O3 polymorphs at the eventual cost of somewhat less heat resistance?
Isostructural gems (Hematite structure)
See: Simple crystal structures of especial interest
Related
- Deltalumite – a tetragonal polymorph of Al2O3 with spinel structure
- Tistarite Ti2O3 has the same structure. => neo-polymorph series?
- Gemstone like compounds with high potential – Gemstone like compounds
- Corundum structure – Simple crystal structures of especial interest
- Aluminum oxides
- Moissanite is also an extremely heat resistant base material.
- Diamond is much less heat and oxidation resistant.
- Both diamond and moissanite have higher crystal structure symmetry than leukosapphire
Polymorphs
Deltalumite Al2O3 (δ form of corundum, polymorph of sapphire) – tetragonal – Mohs ? –
Trivia
- 🟥 Ruby is just red sapphire. Color from Chromium Cr.
- 🟦 Classic blue is from elements (Fe,Ti)
- ⬜️ transparent, no impurities, white sapphire
- 🟨 There are many other possible colors from impurities/dopants.
- 🟢 Emerald is NOT a form of sapphire but a green form of Beryl.
a beryllium aluminum silicate harder than typical silicates.
Beryllium is a quite rare element so forms of beryl are not that viable as a structural material.
External links
Wikipedia
- materialsproject.org [1]
- mineralienatlas (de) [2]
- Strukturtypendatenbank uni-freiburg: [3]
- Wikidata leukosapphire: https://www.wikidata.org/wiki/Q3831236