Difference between revisions of "S-block metals"
(→barely soluble salts (*ates): added phosphates) |
(→barely soluble salts (*ates): enstatite & wollastonite) |
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=== harder compounds (silicates only?) === | === harder compounds (silicates only?) === | ||
| + | * '''Mg'''SiO<sub>3</sub> enstatite <ref>[https://en.wikipedia.org/wiki/Enstatite Wikipedia:Enstatite]</ref> Mohs 5-6 | ||
| + | * '''Ca'''SiO<sub>3</sub> wollastonite <ref>[https://en.wikipedia.org/wiki/Wollastonite Wikipedia:Wollastonite]</ref> Mohs 4.5-5 | ||
| + | ---- | ||
Some harder silicate compounds containing aluminum too are: | Some harder silicate compounds containing aluminum too are: | ||
* '''Li'''Al(SiO<sub>3</sub>)<sub>2</sub> spodumene <ref>[https://en.wikipedia.org/wiki/Spodumene Wikipedia:Spodumene]</ref> Mohs 6.5-7 (contains unabundant lithium) | * '''Li'''Al(SiO<sub>3</sub>)<sub>2</sub> spodumene <ref>[https://en.wikipedia.org/wiki/Spodumene Wikipedia:Spodumene]</ref> Mohs 6.5-7 (contains unabundant lithium) | ||
Revision as of 11:13, 20 December 2015
Contents
s-block metals as material filler
The lighter ones of the alkali- and alkaline earth metals (the non-noble metals in the left s-block of the periodic table) belong to the most abundant elements around. Thus its an iteresting question wheter those elements can be combined with other abundant ones to make structural building materials.
solubility issue
The s-block metals need to be combined with other elements not only because metals are not very suitable for mechanosynthesis but also because they are extremely reactive in pure form. A self passivation oxide layer film like the one that macroscopic blocks of magnesium have is obviously not possible on nano sized building blocks. In contact to air oxidation would go down right to the core of the building block and blow up the part twice in volume destroying it completely.
Since s-block metals are so electropositive they tend to toss away their shell electron or pair of shell electrons and thus tend to form ionic salts. Such a salt usually has the form:
- positively charged s-block-metal + negatively charged nonmetal-acid
Polar salts of this form are easily dissolved in water since water is a polar solvent. But good water solubility is not what one usually wants from a typical building material - especially not if the solvent is toxic like it is the case with many beryllium compounds. So the focus here will be on the few non or barely water soluble compounds.
barely soluble salts (*ates)
harder compounds (silicates only?)
Some harder silicate compounds containing aluminum too are:
- LiAl(SiO3)2 spodumene [3] Mohs 6.5-7 (contains unabundant lithium)
- KAl(SiO3)2 leucite [4] Mohs 5.5-6
- NaAl(SiO3)2 jadeite (a chain/band silicate) [5] Mohs 6.5-7
- NH4[AlSi3O8] buddingtonite [6] Mohs 5.5 (insoluble ammonium compound!)
- Li[AlSi3O8] (unknown? - in literature - are there crystals?)
- K[AlSi3O8] orthoclase [7] (feldspar member) Mohs 6 (defining mineral) and amazonite [8] Mohs 6-6.5 and sanidine (endmember?) [9] Mohs 6 and microline [10] Mohs 6-6.5
- Na[AlSi3O8] albite (sodium placgioclase feldspar) [11] Mohs 6-6.5
- LiAlSi4O10 petalite [12] Mohs 6-6.5
- KAlSi4O10 (unknown? potassium petalite)
- NaAlSi4O10 sodium petalite
- CaAl2Si2O8 anorthite (calcium plagioclase feldspar) [13] Mohs 6
- MgAl2Si2O8 magnesium aluminosilicate (there are various associated hydroxide minerals => solubility?)
- Fe or Cr replacing Al => unknown
Garnets containing aluminum:
- Ca3Al2(SiO4)3 grossularite [14] Mohs 7-7.5 (an ugrandite garnet and nesosilicate)
- Mg3Al2(SiO4)3 pyrope [15] Mohs 7-7.5 (a pyralspite garnet and nesosilicate)
Ugrandite garnets are defined by their calcium content:
- Ca3Al2(SiO4)3 grossularite Mohs 7-7.5
- Ca3Fe2(SiO4)3 andardite [16] Mohs 6.5-7
- Ca3Cr2(SiO4)3 uvarovite [17] Mohs 6.5-7 (contains unabundant chromium)
Magnesium analogs to ugrandite garnets:
- Mg3Al2(SiO4)3 pyrope Mohs 7-7.5
- Mg3Fe2(SiO4)3 (unknown?)
- Mg3Cr2(SiO4)3 Knorringite [18] Mohs 6-7
harder compounds (phosphates)
- MgAl2(PO4)2(OH)2 magnesium lazulite [19] Mohs 5.5-6
- CaAl2(PO4)2(OH)2 gatumbaite Mohs 4-5
softer compounds
When systematically building combinations of s-block metals and d-block nonmetal acids one can find some barely soluble compounds:
- calcium carbonate CaCO3 (limestone/chalk ... calcite/aragonite/vaterite)
- calcium phosphates (similar to hydroxyapatit bone tooth-enamel)
- calcium silicate CaSiO3 (dry wall plates ... wollastonite)
- magnesium silicate Mg2SiO4 (forsterite - no crystal water - pretty hard - neosilicate - earth mantle mineral)
- magnesium silicate Mg3Si4O10(OH)2 (talc - a hydroxide - way too soft for a building material)
Beryllium silicates:
- beryl Be3Al2(SiO3)6 (cyclosilicate) wikipedia
varieties: emerald (green Cr), aquamarine (blue Fe), red beryl (red Mn), goshenite (colorless), heliodor (yellow Fe), and morganite (pink Mn) - phenakite Be2SiO4 (neosilicate)
- bertrandite Be4Si2O7(OH)2 (hydorxide - pretty hard - sorosilicate)
non salts but (*ides)
Probably the simplest barely soluble earth alkali compounds (that are not salts) are:
- MgO (periclase ... magnesia) magnesium oxide (nontoxic)
- CaF2 (fluorite) calcium fluoride
- BeO (brommelite Mohs 9) [20] beryllium oxide
- BeAl2O4 chrysoberyl
[todo:]
- [find some insoluble alkali compounds Li Na K]
- [maybe find some compounds of the heavier and less abundant ones (Rb & Cs) (Sr & Ba)]
- [treat aluminum as special case]
External links
- ↑ Wikipedia:Enstatite
- ↑ Wikipedia:Wollastonite
- ↑ Wikipedia:Spodumene
- ↑ Wikipedia:Leucite
- ↑ Wikipedia:Jadeite
- ↑ Wikipedia:Buddingtonite
- ↑ Wikipedia:Orthoclase
- ↑ Wikipedia(de):Amazonit
- ↑ Wikipedia:Sanidine
- ↑ Wikipedia(de):Mikrolin
- ↑ Wikipedia:Albite
- ↑ Wikipedia:Petalite
- ↑ Wikipedia:Anthorite
- ↑ Wikipedia:Grossular
- ↑ Wikipedia:Pyrope
- ↑ Wikipedia:Andradite
- ↑ Wikipedia:Uvarovite
- ↑ Wikipedia:Knorringite
- ↑ Wikipedia:Lazulite
- ↑ Wikipedia:Brommelite
