Datolite Mineral Data

General Datolite Information

Chemical Formula:

CaBSiO4(OH)

Composition:

Molecular Weight = 159.98 gm

Calcium 25.05 % Ca 35.05 % CaO

Silicon 17.56 % Si 37.56 % SiO₂

Boron 6.76 % B 21.76 % B₂O₃

Hydrogen 0.63 % H 5.63 % H₂O

Oxygen 50.00 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaB(SiO₄)(OH)

Environment:

Secondary mineral in basic igneous rocks.

IMA Status:

Valid Species (Pre-IMA) 1806

Locality:

Diabases of the Connecticut River valley, USA. Link to MinDat.org Location Data.

Name Origin:

From the Greek, dateisthai, meaning "to divide," because granular aggregates crumble readily.

Name Pronunciation:

Datolite

Synonym:

ICSD 22026

PDF 36-429

Datolite Image

Images:

Datolite

Comments: Cluster of doubly-terminated datolite crystals to 3.3 cm across with a scattering of brown inclusions.
Location: Boron Pit, Dal'Negorsk, Russia. Scale: 5x3.9x3.7 cm.
© Fabre Minerals

Datolite Crystallography

Axial Ratios:

a:b:c =1.2643:1:0.6321

Cell Dimensions:

a = 9.66, b = 7.64, c = 4.83, Z = 4; beta = 90.15° V = 356.46 Den(Calc)= 2.98

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/c

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.114(1), 2.855(0.65), 2.189(0.6),

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Forms: ( 1 1 0) ( 0 1 1) ( 1 1 2) ( 1 0 0) ( 1 1 1)

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Physical Properties of Datolite

Cleavage:

None

Color:

Brown, Colorless, Yellow, White, Light green.

Density:

2.8 - 3, Average = 2.9

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Porcelainous - Fine-grained, translucent massive material like broken china

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5.5 - Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Datolite

Gladstone-Dale:

CI meas= -0.03 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.002 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2181,KPDmeas= 0.2241,KC= 0.2177
Ncalc = 1.61 - 1.65

Optical Data:

Biaxial (-), a=1.626, b=1.653-1.654, g=1.67, bire=0.0440, 2V(Calc)=72-74, 2V(Meas)=74. Dispersion none.

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Calculated Properties of Datolite

Electron Density:

Bulk Density (Electron Density)=2.98 gm/cc
note: Specific Gravity of Datolite =2.98 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Datolite= 3.83 barns/electron
U=PE_Datolite x rElectron Density= 11.41 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Datolite is Not Radioactive

Datolite Classification

Dana Class:

54.02.01a.01 (54)Nesosilicate Borosilicates and Some Beryllosilicates

(54.02)with B in [4] coordination

(54.02.01a)Datolite group (Datolite series)

54.02.01a.01 Datolite CaBSiO4(OH) P 2₁/c 2/m

54.02.01a.02 Hingganite-(Ce) (Ce,Ca)2([],Fe)Be2Si2O8[(OH),O]2 P 2₁/a 2/m

54.02.01a.03 Hingganite-(Y) Y2([])Be2Si2O8(OH)2 P 2₁/a 2/m

54.02.01a.04 Hingganite-(Yb) (Yb,Y)2([])Be2Si2O8(OH)2 P 2₁/a 2/m

54.02.01a.05 Calcybeborosilite-(Y)! (REE,Ca)2[](B,Be)2(SiO4)2(OH,O)2 P 2₁/a 2/m

Strunz Class:

09.AJ.20 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AJ -Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra,

09.AJ.20 Bakerite Ca4B4(BO4)(SiO4)3(OH)3•(H2O) P 2₁/c 2/m

09.AJ.20 Calcybeborosilite-(Y)! (REE,Ca)2[](B,Be)2(SiO4)2(OH,O)2 P 2₁/a 2/m

09.AJ.20 Calciogadolinite? CaREE(Fe)Be2Si2O10 P 2₁/a 2/m

09.AJ.20 Datolite CaBSiO4(OH) P 2₁/c 2/m

09.AJ.20 Hingganite-(Yb) (Yb,Y)2([])Be2Si2O8(OH)2 P 2₁/a 2/m

09.AJ.20 Homilite Ca2(Fe,Mg)B2Si2O10 P 2₁/a 2/m

09.AJ.20 Gadolinite-(Ce) (Ce,La,Nd,Y)2FeBe2Si2O10 P 2₁/c 2/m

09.AJ.20 Gadolinite-(Y) Y2FeBe2Si2O10 P 2₁/a 2/m

09.AJ.20 Hingganite-(Ce) (Ce,Ca)2([],Fe)Be2Si2O8[(OH),O]2 P 2₁/a 2/m

09.AJ.20 Hingganite-(Y) Y2([])Be2Si2O8(OH)2 P 2₁/a 2/m

09.AJ.20 Melanocerite-(Ce) (Ce,Th,Ca)5(Si,B)3O12(OH,F)•n(H2O)(?) Unk (HEX-R) Trig

09.AJ.20 Minasgeraisite-(Y) CaY2Be2Si2O10 P 2₁/a 2/m

Other Datolite Information

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Datolite

CaBSiO4(OH)
Dana No: 54.02.01a.01 Strunz No: 09.AJ.20
Locality:

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