Ternary and higher gem-like compounds

This page is about:

• looking through materials made out of three chemical elements (somewhat systematically) and
• checking for their potential usefulness as mechanical base materials for
  mechanical metamaterials in future advanced atomically precise technology.

The focus of this page is on ternary materials. That is materials made out of three elements.
Three is still a small number and may make for simpler crystal structures.

• A part of the materials here are the the salts of oxoacids that add just one type of metal.
• A part of the materials here are rock forming minerals.

Metastable materials

Note that with mechanosynthesis it is possible to control solid solutions series in a novel non-statistical manner.

With creation of materials by melting and recrystallisation (that is the "normal" thermodynamic means of today) atoms that are chemically similar often can and will not form regular patterns on cooling and solidifying but remain in a mixed chaotic state.

When materials are created via mechanosynthesis (which does not involve heating the material) then the atoms can be deliberately placed in (within bounds) arbitrary non random checkerboard-patterns on any scales. And the atoms will stay there (at their entropically unstable position) as long as the material is not heated so much that notable diffusion sets in. Room temperature and quite way above can be ok for. It all depends on the particular design in question.

See "pseudo phase diagrams" and "neo-polymorphs" for more information.

most common metal rich core mantle transition zone minerals

In the earths mantle and crust silicon and oxygen are the most abundant elements. On the borther to earths outer core this changes to iron and nickle. Down there the most abundant minearls are made from mixture of those elements. As a sidenote: In nature when iron rich metal is available in stochiometric excess heterogenous pallasite is formed. This rock looks really beautiful and can be found in some meteroids - recommendation to check it out.

Mixing series of olivine (wikipedia) / peridot (wikipedia) - (Mg,Fe)2SiO4 With high pressure modifications:

• Mg₂SiO₄ wadseylite (wikipedia) – sorosilicate – ortorhombic – dipyramidal – Mohs ??
• Mg₂SiO₄ ringwoodite (wikipedia) – nesosilicate – cubic – Mohs ??

Of interest as diamondoid materials may be the pure end members of the mixing series:

• Fayalite Fe₂SiO₄ – orthorhombic dipyramidal – Mohs 6.5-7.0
• Forsterite Mg₂SiO₄ – orthorhombic dipyramidal – Mohs 7
• Tephroite Mn₂SiO₄ (less interesting since Mn is more scarce) – orthorhombic dipyramidal – Mohs 6
• Titanium Silicate TiSiO₄ [1] (broken)

Related minerals:

• Ca(Mg,Fe)SiO₄ - wikipedia: magnesium and iron monticellite – orthorhombic dipyramidal – Mohs 5.5
• CaTiSiO₅ - wikipedia: Titanite or Sphene (optical dispersion exceeding diamond; birefringent) – monoclinic – Mohs 5.0-5.5
• Mn₃Al₂(SiO₄)₃ - wikipedia: spessartine - (with rather rare Manganese) – cubic – Mohs 6.5-7.0
• FeTiO₃ - wikipedia: Ilmenite – trigonal rhombohedral – Mohs 5-6

The following aluminosilicates are susceptible to heat (200°C)

• Al₂SiO₅ kyanite Wikipedia:Kyanite – triclinic – Mohs 4.5-5.0 & 6.5-7.0 (highly anisotropic)
• Al₂SiO₅ andalusite Wikipedia:Andalusite – ortorhombic dipyramidal – Mohs 6.5-7.5
• Al₂SiO₅ sillimanite Wikipedia:Sillimanite – ortorhombic dipyramidal – Mohs 7

The spinell group (wikipedia)

These oxide minerals are devoid of the ubiquitously present silicon.

aluminum spinells

• MgAl₂O₄ - wikipedia: spinel - Mohs 7.5 to 8.0
• FeAl₂O₄ - wikipedia: hercynite - Mohs 7.5
• (Mg,Fe)Al₂O₄ - wikipedia: caylonite - mixing series inbetween the former two - Mohs 7.5 to 8.0
• ZnAl₂O₄ - wikipedia: gahnite - Mohs 7.5 to 8.0
• BeAl₂O₄ - wikipedia: crysoberyll - Mos 8.5
• MnAl₂O₄ - wikipedia: galaxite - (with rather rare manganese) - image - Mohs 7.5

iron spinells

• MgFe₂O₄ - wikipedia: magnesioferrite - Mohs 6.0 to 6.5
• TiFe₂O₄ - wikipedia: ulvöspinel - Mohs 5.5 to 6.0
• ZnFe₂O₄ - wikipedia: franklinite - Mohs 5.5 to 6.0
• NiFe₂O₄ - wikipedia: trevorite - Mohs 5.0
• MnFe₂O₄ - wikipedia: jacobsite - (with rather rare manganese) - Mohs 5.5 to 6.0

related compound:

• ZnFe₃O₄ - wikipedia: zinc ferrite - synthetic zinc ferrites

Pseudobrookite group - common in titanium rich lunar soil

From wikipedia page Armacolite: "End members are armalcolite ((Mg,Fe)Ti₂O₅), pseudobrookite (Fe₂TiO₅), ferropseudobrookite (FeTi₂O₅) and karrooite (MgTiO₅). They are isostructural and all have orthorhombic crystal structure and occur in lunar and terrestrial rocks."

• Fe₂TiO₅ wikipedia: Pseudobrookite (Mohs 6)

Related compounds:

• Fe₂Ti₃O₉ Pseudorutil (de) (Mohs 3)
• (Fe,Ca)SiO₃ Pyroxferroite (Mohs 4.5-5.5)

Alkali and earth alkali compounds

They tend to be rather soluble in binary compounds (you won't find many there) in ternary and higher compounds they tend to form less water soluble minerals. See: compounds with s-block metals

• Ca(OH)₂ calcium hydroxide aka slaked lime (rather water soluble)
• CaCO₃ calcium carbonate (very slightly soluble)
• MgCO₃ magnesium carbonate aka magnesite (slightly soluble)
• Mg₃B₇O₁₃Cl boracite (very slightly water soluble)

Other

• Various silicates [2]

• Sinoinite (SiNO) somewhere in the pseudo phase diagram that spans a triangle between silicon oxygen and nitrogen where also the more widely known binary stochiometries SiO₂ and Si₃N₄ lie.

Another interesting tertiary material falling in this scheme would be CSiO ₄
a solid intermediate material between CO₂(gas) SiO₂(solid quartz): [3] (A prototypical pseudo phase diagram.)

• CaTiO₃ – Perovskite
• BaTiO₃
• SrTiO₃
• ZrTiO₃ tp PbTiO₃ – Lead zirconium titanate

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• AlPO₄ berlinite Wikipedia:Berlinite Mohs 6.5 (similar to quartz)
• MnCO₃ rhodochrosite [4] Mohs 3.5-4
• MnSiO₃ rhodonite [5] Mohs 5.5-6.5
• Na₄Al₃Si₉O₂₄Cl marialite Mohs 5.5-6 (scapolite end member)
• Ca₄Al₆Si₆O₂₄CO₃ meionite Mohs 5-6 (scapolite end member)
• Cu₂FeSnS₄ stannite [6] (contains unabundant copper and tin) Mohs 4
• CuFeS₂ calcopyrite [7] Mohs 3.5 (unabundant copper | metallic gold)
• CuFe₂S₃ cubanite Mohs 3.5-4 orthorhombic
• Fe₉Ni₉S₁₆ pentlandite [8] (Mohs 3.5-4 cubic)

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• Bastnäsite – (La, Ce, Y)CO₃F – rare earth fluorine containing carbonate – hexagonal – Mohs 4-5

MAX phases [9] … layered, hexagonal carbides and nitrites exhibiting both metallic and ceramic characteristics.
The max phases made form the mosts abundant elements are the ones with titanium as M and rock forming elements (Si or Al) as A:
211: Ti₂AlC, Ti₂AlN, Ti₂SC
312: Ti₃AlC₂, Ti₃SiC₂
413: Ti₄AlN₃, Ti₄SiC₃
Some MAX phases with rare but not extremely rare elements:
211 M = Ti: Ti₂PbC, Ti₂SnC, Ti₂ZnC, Ti₂ZnN
211 M = Zr: Zr₂AlC, Zr₂SC, Zr₂PbC, Zr₂SnC
211 M = Cr: Cr₂AlC
211 M = V: V₂AlC, V₂PC, V₂ZnC
211 M = Nb: Nb₂AlC, Nb₂SC, Nb₂PC, Nb₂SnC, Nb₂CuC
211 A = Al: Zr₂AlC, Cr₂AlC, V₂AlC, Nb₂AlC
211 A = Cu: Nb₂CuC
211 A = Pb: Ti₂PbC, Zr₂PbC
211 A = Sn: Ti₂SnC, Zr₂SnC, Nb₂SnC
211 A = Zn: Ti₂ZnC, Ti₂ZnN, V₂ZnC
211 A = S: Zr₂SC, Nb₂SC
211 A = P: V₂PC, Nb₂PC
312: Ti₃SnC₂, Ti₃ZnC₂, Zr₃AlC₂, V₃AlC₂
413: V₄AlC₃, Nb₄AlC₃
MAX phases with highly rare elements like (Sc,Mo,Hf,Ta; Cd,Ga,In,Tl,Hf,Ge,As) have been excluded from the listing here.

Aluminium silicates

• Hydrody Topaz Al₂SiO₄(OH)₂

There are many aluminium silicate minerals [10] like:

• Al₂SiO₅ Andalusite [11] & Sillimanite [12] (Mohs 6.5-7)
• Al₆Si₂O₁₃ Mullite [13] (Mohs 6-7)
• Al₂SiO₅ Kyanite [14] (Mohs 4.5-7 anisotropic)

Related

• Base materials with high potential
• Simple crystal structures of especial interest

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• Binary diamondoid compound
• Diamondoid compound
• Salts of oxoacids