Mineral phase
IMA name
Donpeacorite
Class
silicate mineral
Compound type
inosilicate
Comments
Donpeacorite: name by extension of (Fe,Mn,Mg)2Si2O6 in the range Fe=0-10%, Mn>10% - Mass, density and optical properties for Mn0.5Mg1.5.[SiO3]2 (x=0.5)
Formula
(Mn2+x,Mg1x)Mg.[SiO3]2      where x=01
Chemical formula
(Mn2+,Mg)MgSi2O6
Elemental formula
(Mn2+)0-1 (Mg)1-2 Si2 O6
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Mn2+ Manganese(II) cation element 0 - 1 constituent element main
Mg Magnesium element 1 - 2 constituent element main
Si Silicon element 2 constituent element main
O Oxygen element 6 constituent element main
Composition comments
Common substitution: Fe2+ - Common impurities: Al, Fe3+, Ca, Na
Oxides
Formula MnO MgO SiO2
Mass fraction (%) 23.78 22.52 53.71
Oxides comments
for Mn0.5Mg1.5.[SiO3]2 (x=0.5)

Strunz

Class
silicates (09)
Division
inosilicate (09.D)
Family
with 2-periodic single chains, Si2O6; pyroxene family (09.DA)
Code
09.DA.05

Dana

Major class
silicates (VIII)
Class
inosilicate single-width unbranched chains, w=1 (65)
Type
with chains P=2 (65.01)
Group
Orthopyroxenes (65.01.02)
Code
65.01.02.03
Phase type
crystalline
Crystal system
orthorhombic
Crystal class
dipyramidal
Crystal class symbol
mmm (D2h)
Crystal spacegroup
Pbca
Molar mass
200.78 - 231.41 g/mol
Density
3.36 g/cm3
State NTP
solid
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.015
Refraction index nα
1.677
Refraction index nβ
1.684
Refraction index nγ
1.692
Dispersion V
weak
Pure color
yellow
Color
yellow-orange
Diaphaneity
transparent to translucent
Luster
vitreous