Beryl Mineral Data

General Beryl Information

Chemical Formula:

Be3Al2Si6O18

Composition:

Molecular Weight = 537.50 gm

Beryllium 5.03 % Be 13.96 % BeO

Aluminum 10.04 % Al 18.97 % Al₂O₃

Silicon 31.35 % Si 67.07 % SiO₂

Oxygen 53.58 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Be₃Al₂Si₆O₁₈

Environment:

Mainly granitic pegmatites.

IMA Status:

Valid Species (Pre-IMA) Prehistoric

Locality:

Pala pegmatite District, San Diego Co., California for morganite. Columbia for emeralds. Russia for heliodor. Link to MinDat.org Location Data.

Name Origin:

From the ancient Greek, beryllos, signifying a "precious blue-green color of sea water" stone, but through later usage, applied only to beryl.

Name Pronunciation:

Beryl

Synonym:

Aquamarine - Blue varitey

Emerald - green

Goshenite - colorless

Heliodor - yellow

ICSD 2791

Morganite - pink

PDF 9-430

Beryl Image

Images:

Beryl

Comments: Transparent Goshenite, the colorless variety of beryl with orthoclase and muscovite.
Location: Pingwu, Sichuan, China. Scale: 9 x 8.5 cm.
© Fabre Minerals

Images:

Beryl

Comments: Transparent Aquamarine, the blue variety of beryl.
Location: Nagar, Pakistan. Scale: 3 x 4 x 8.5 cm.
© Dan Weinrich

Images:

Beryl Calcite

Comments: Transparent emerald, the green variety of beryl on calcite (marble) matrix.
Location: Coscuez, BoyacÃ¡, Colombia. Scale: 2.5 x 2.5 cm.
© Fabre Minerals

Images:

Beryl

Comments: Transparent Morganite, the pink variety of beryl.
Location: Nuristan, Laghman Province, Afghanistan. Scale: 9.2 x 6.5 cm.
© John Veevaert

Images:

Beryl

Comments: Transparent Heliodor, the yellow variety of beryl.
Location: Wolodarsk, Wolynsky, Ukraine. Scale: 2.8 x 0.7 cm.
© John Veevaert

Images:

Beryl

Comments: Red beryl prism on rhyolite matrix.
Location: Violet claims, Wah Wah Mountains, Beaver County, Utah, USA. Scale: Size Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Apatite-(CaF) Beryl Muscovite Apatite

Comments: Pink crystals of fluorapatite with pale blue beryl (aquamarine) on books of muscovite crystals.
Location: Nagar area, Gilgit district, Northern Areas, Pakistan. Scale: 3 x 3 cm.
© Dan Weinrich

Beryl Crystallography

Axial Ratios:

a:c = 1:0.9975

Cell Dimensions:

a = 9.215, c = 9.192, Z = 2; V = 675.98 Den(Calc)= 2.64

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6/mmc

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

By Intensity(I/I_o): 2.867(1), 3.254(0.95), 7.98(0.9),

Forms:

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

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Physical Properties of Beryl

Cleavage:

{0001} Imperfect

Color:

Green, Blue, Yellow, Colorless, Pink.

Density:

2.63 - 2.9, Average = 2.76

Diaphaneity:

Transparent to subtranslucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Columnar - Forms columns

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

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

Hardness:

7.5-8

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Resinous

Streak:

white

Optical Properties of Beryl

Dichroism (e):

yellowish green, colorless, or colorless.

Dichroism (w):

bluish green, blue, or pink.

Gladstone-Dale:

CI meas= 0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.039 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2205,KPDmeas= 0.2106,KC= 0.2123
Ncalc = 1.56 - 1.62

Optical Data:

Uniaxial (-), e=1.564-1.595, w=1.568-1.602, bire=0.0040-0.0070.

Calculated Properties of Beryl

Electron Density:

Bulk Density (Electron Density)=2.74 gm/cc
note: Specific Gravity of Beryl =2.77 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_Beryl= 1.55 barns/electron
U=PE_Beryl x rElectron Density= 4.24 barns/cc.

Radioactivity:

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

Beryl Classification

Dana Class:

61.01.01.01 (61)Cyclosilicate Six-Membered Rings

(61.01)with [Si6O18] rings; possible (OH) and Al substitution

(61.01.01)Beryl group

61.01.01.01 Beryl Be3Al2Si6O18 P 6/mmc 6/m 2/m 2/m

61.01.01.02 Bazzite Be3(Sc,Al)2Si6O18 P 6/mcc 6/m 2/m 2/m

61.01.01.03 Indialite Mg2Al4Si5O18 P 6/mcc 6/m 2/m 2/m

61.01.01.04 Stoppaniite! (Fe,Al,Mg)4(Na,[])2[Be6Si12O36]•2(H2O) P 6/mmc 6/m 2/m 2/m

61.01.01.05 Pezzottaite! Cs(Be2Li)Al2Si6O18 R 3c 3m

Strunz Class:

09.CJ.05 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CJ -[Si6O18]12- 6-membered single rings (sechser-Einfachringe),

09.CJ.05 Beryl Be3Al2Si6O18 P 6/mmc 6/m 2/m 2/m

09.CJ.05 Bazzite Be3(Sc,Al)2Si6O18 P 6/mcc 6/m 2/m 2/m

09.CJ.05 Indialite Mg2Al4Si5O18 P 6/mcc 6/m 2/m 2/m

09.CJ.05 Stoppaniite! (Fe,Al,Mg)4(Na,[])2[Be6Si12O36]•2(H2O) P 6/mmc 6/m 2/m 2/m

09.CJ.05 Pezzottaite! Cs(Be2Li)Al2Si6O18 R 3c 3m

Other Beryl Information

References:

NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

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Beryl

Be3Al2Si6O18
Dana No: 61.01.01.01 Strunz No: 09.CJ.05
Locality:

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