Mineralogy Database

Danburite Mineral Data

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General Danburite Information

Help on Chemical  Formula: Chemical Formula: CaB2(SiO4)2
Help on Composition: Composition: Molecular Weight = 245.86 gm
   Calcium  16.30 %  Ca   22.81 % CaO
   Silicon  22.85 %  Si   48.88 % SiO2
   Boron     8.79 %  B    28.32 % B2O3
   Oxygen   52.06 %  O
           ______        ______ 
           100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: CaB2Si2O8
Help on Environment: Environment: Contact metamorphic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1839
Help on Locality: Locality: Danbury, Connecticut. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after its location.
Help on Name Pronunciation: Name Pronunciation: Danburite + Pronunciation Say DANBURITE
Help on Synonym: Synonym: ICSD 6254
  PDF 29-304

Danburite Image

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Comments: Very-fine, large, single transparent crystal of danburite with minor crystals of colorless calcite all around the base.
Location: Charcas, San Luis Potosi, Mexico. Scale: 4 x 2.5 x 9.5 cm.
© Dan Weinrich

Danburite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9184:1:0.8822
Help on Cell Dimensions: Cell Dimensions: a = 8.048, b = 8.763, c = 7.731, Z = 4; V = 545.23 Den(Calc)= 3.00
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnam
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.564(1), 2.654(0.75), 2.961(0.7),

Physical Properties of Danburite

Help on Cleavage: Cleavage: {001} Poor
Help on Color: Color: Colorless, White, Gray, Brownish white, Straw yellow.
Help on Density: Density: 2.97 - 3.02, Average = 2.99
Help on Diaphaneity: Diaphaneity: Transparent to translucent
Help on Fracture: Fracture: Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Help on Habit: Habit: Disseminated - Occurs in small, distinct particles dispersed in matrix.
Help on Habit: Habit: Euhedral Crystals - Occurs as well-formed crystals showing good external form.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 7 - Quartz
Help on Luminescence: Luminescence: Fluorescent and thermoluminescent (red), Short UV=violet blue, Long UV=blue to blue-green.
Help on Luster: Luster: Vitreous - Greasy
Help on Streak: Streak: white

Optical Properties of Danburite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.004 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.003 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.211,KPDmeas= 0.2114,KC= 0.2104
Ncalc = 1.63 - 1.64
Help on Optical Data: Optical Data: Biaxial (+/-), a=1.63, b=1.633, g=1.636, bire=0.0060, 2V(Calc)=88, 2V(Meas)=88-90. Dispersion relatively strong.

Calculated Properties of Danburite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.98 gm/cc
note: Specific Gravity of Danburite =3.00 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PEDanburite = 2.99 barns/electron
U=PEDanburite x rElectron Density= 8.89 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Danburite is Not Radioactive

Danburite Classification

Help on  Dana Class: Dana Class: (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O
  (56.03)with [Si2O7] with borate groups
  (56.03.01)Danburite Goup Danburite CaB2(SiO4)2 Pnam 2/m 2/m 2/m Maleevite! BaB2Si2O8 P nma 2/m 2/m 2/m Pekovite! SrB2Si2O8 P nma 2/m 2/m 2/m
Help on  Strunz Class: Strunz Class: 09.FA.65 09 - SILICATES (Germanates)
  09.F - Tektosilicates without Zeolitic H2O
  09.FA -Tektosilicates without additional non-tetrahedral anions, (Al,B):Si = 1:1
09.FA.65 Danburite CaB2(SiO4)2 Pnam 2/m 2/m 2/m
09.FA.65 Maleevite! BaB2Si2O8 P nma 2/m 2/m 2/m
09.FA.65 Pekovite! SrB2Si2O8 P nma 2/m 2/m 2/m

Other Danburite Information

Help on References: References: NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
Help on See Also: See Also: Links to other databases for Danburite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - CalTech Mineral Spectroscopy
5 - EUROmin Project
6 - Ecole des Mines de Paris
7 - GeoScienceWorld
8 - Glendale Community College
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - HyperPhysics
14 - MinDAT
15 - Mineralienatlas (Deutsch)
16 - Online Mineral Museum
17 - QUT Mineral Atlas
18 - Ruff.Info
19 - Tradeshop.com - The Rainbow of Gems
21 - theimage

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Dana No: Strunz No: 09.FA.65





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