17.0

	Formula	Name	Family	Number min-max	Mole fraction	Isotope mole fraction	State	Relevance
	$Mg$	Magnesium	element	2	0.23529411764705882	1.0	pure	main
	$Si$	Silicon	element	1 - 2	0.17647058823529413 $\pm$ 0.058823529411764705	1.0	pure	main
	$O$	Oxygen	element	4 - 6	0.5882352941176471 $\pm$ 0.11764705882352941	1.0	pure	main

Class

molecular solids with apolar molecules (01)

Type

with monoatomic apolar molecules (A) (01.01)

Phase type

crystalline

Crystal system

orthorhombic

Crystal class

dipyramidal

Crystal class symbol

mmm (D2h)

Refringence type

biaxial

Refringence sign

positive or negative

Birefringence

0.009 - 0.033

Refraction index $n_{\alpha}$

1.636 - 1.668

Refraction index $n_{\beta}$

1.650 - 1.673

Refraction index $n_{\gamma}$

1.659 - 1.679