Synthetic olivine group | SSHADE

Solid phase

Official name: Synthetic olivine group

Family: ionic solid
Class: mixed salt
Compound type: nesosilicate

Chemical composition

Formula: $(A^{2,3+})_{2-3}(SiO_4^{4-})_{1-2}\ \ \ \ \$ with $A = Mg^{2+}, Fe^{2+}, Fe^{3+}, Mn^{2+}$ or $Ni^{2+}$
Chemical formula: (Mg,Fe,Mn,Ni)(2-3)(SiO4)(1-2)
Elemental formula: (Mg2+)0-2 (Fe2+)0-2 (Fe3+)0-2 (Ni2+)0-2 (Mn2+)0-2 (Si)1-2 (O-)4-8
Isotope mixture type: terrestrial abundance

13.0

	Formula	Name	Family	Number min-max	Mole fraction	Isotope mole fraction	State	Relevance
	$Mg^{2+}$	Magnesium(II) cation	element	0 - 2	0.15384615384615385 $\pm$ 0.15384615384615385	1	constituent cation	main
	$Fe^{2+}$	Iron(II) cation	element	0 - 2	0.15384615384615385 $\pm$ 0.15384615384615385	1	constituent cation	main
	$Fe^{3+}$	Iron(III) cation	element	0 - 2	0.15384615384615385 $\pm$ 0.15384615384615385	1	constituent cation	main
	$Ni^{2+}$	Nickel cation	element	0 - 2	0.15384615384615385 $\pm$ 0.15384615384615385	1	constituent cation	main
	$Mn^{2+}$	Manganese(II) cation	element	0 - 2	0.15384615384615385 $\pm$ 0.15384615384615385	1	constituent cation	main
	$(SiO_4)^{4-}$	Silicate anion	chemical function	1 - 2	0.23076923076923078 $\pm$ 0.07692307692307693	1	anionic radical	main

Chemical functions and bonds

Chemical bonds

	Bond	Number
	$\cdot Mg^{2+} \cdot O^{-}-$
	$\cdot Fe^{2+} \cdot O^{-}-$
	$\cdot (\cdot) Fe^{3+} \cdot O^{-}-$
	$\cdot Ni^{2+} \cdot O^{-}-$
	$\cdot Mn^{2+} \cdot O^{-}-$

Class: mixed salts (08)

Endmembers and polymorphs

Endmembers

Synthetic fayalite

Associated phases

Equivalent mineral: Olivine group

Crystallography

Phase type: crystalline
Crystal system: various
Crystal class: various
Crystal class symbol: various
Crystal spacegroup: various
Comments: mostly orthorhombic system except 1 member. In Mindat the group also includes A=Ca^{2+}

Physical properties

Molar mass: 140.69-351.71 $g/mol$
Density: 3.21-4.6 $g/cm^3$

Thermodynamical properties

State NTP: solid

Optical properties

Refringence type: biaxial

Links and Publications

Links