Gyrolite Mineral Data

General Gyrolite Information

Chemical Formula:

NaCa16Si23AlO60(OH)8•64(H2O)

Composition:

Molecular Weight = 3,586.19 gm

Sodium 0.64 % Na 0.86 % Na₂O

Calcium 17.88 % Ca 25.02 % CaO

Aluminum 0.75 % Al 1.42 % Al₂O₃

Silicon 18.01 % Si 38.54 % SiO₂

Hydrogen 3.82 % H 34.16 % H₂O

Oxygen 58.89 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaCa₁₆Si₂₃AlO₆₀(OH)₈•64(H₂O)

Environment:

Secondary mineral from the alteration of basalts. Pegmatite dike intruding limestone.

IMA Status:

Valid Species (Pre-IMA) 1851

Locality:

Isle of Skye, Scotland, UK. Link to MinDat.org Location Data.

Name Origin:

From the Greek guros = "circle", in allusion to the round form of the crystalline groupings.

Name Pronunciation:

Gyrolite

Synonym:

Centrallasite

ICSD 68199

PDF 42-1452

Gyrolite Image

Images:

Gyrolite

Comments: Two round beige gyrolite aggregates each about 5cm diameter.
Location: Bombay, India. Scale: Specimen size 10cm.
© John Attard

Gyrolite Crystallography

Axial Ratios:

a:c = 1:13.66255

Cell Dimensions:

a = 9.72, c = 132.8, Z = 5; V = 10,865.79 Den(Calc)= 2.74

Crystal System:

Hexagonal - PyramidalH-M Symbol (6) Space Group: P 6₁

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

By Intensity(I/I_o): 3.12(1), 22(1), 11(0.8),

Crystal Structure:

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Merlino S , Mineralogical Magazine , 52 (1988) p.377-387, Gyrolite: its crystal structure and crystal chemistry, Locality: Qarusait, Greenland, Note: x-coordinate of O102 adjusted to match reported bond lengths, Note: occupancies invented to match formula, Locality: Qarusait, Greenland

Physical Properties of Gyrolite

Cleavage:

{???} Perfect

Color:

Brown, Colorless, Yellow, White, Light green.

Density:

2.45 - 2.51, Average = 2.48

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Compact - Occurs as a compact mass.

Habit:

Lamellar - Thin laminae producing a lamellar structure.

Habit:

Platy - Sheet forms (e.g. micas).

Hardness:

2.5 - Finger Nail

Luminescence:

Fluorescent, Short UV=white, Long UV=white.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Gyrolite

Gladstone-Dale:

CI meas= 0.134 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.217 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1985,KPDmeas= 0.2194,KC= 0.2534
Ncalc = 1.62 - 1.69

Optical Data:

Biaxial (-), a=1.535, b=1.548, g=1.549, bire=0.0140

Calculated Properties of Gyrolite

Electron Density:

Bulk Density (Electron Density)=2.57 gm/cc
note: Specific Gravity of Gyrolite =2.48 gm/cc.

Fermion Index:

Fermion Index = 0.0089417003
Boson Index = 0.9910582997

Photoelectric:

PE_Gyrolite= 2.94 barns/electron
U=PE_Gyrolite x rElectron Density= 7.55 barns/cc.

Radioactivity:

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

Gyrolite Classification

Dana Class:

73.02.02c.01 (73)Phyllosilicate Condensed Tetrahedral Sheets

(73.02)with double and single layers

(73.02.02c)Reyerite group (Gyrolite Subgroup)

73.02.02c.01 Gyrolite NaCa16Si23AlO60(OH)8•64(H2O) P 6₁ 6

Strunz Class:

09.EE.30 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EE -Single tetrahedral nets of 6-membered rings

09.EE.30 Gyrolite NaCa16Si23AlO60(OH)8•64(H2O) P 6₁ 6

09.EE.30 Tungusite [Ca14(OH)8](Si8020)(Si8020)2[Fe9(OH)14] P1 1

Other Gyrolite Information

References:

NAME( Ford32) PHYS. PROP.(Collectors Book of Fluorescent Minerals) OPTIC PROP.(Ford32)

See Also:

Links to other databases for Gyrolite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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Ask about Gyrolite here :
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Print or Cut-and-Paste your Gyrolite Specimen Label here :

Gyrolite

NaCa16Si23AlO60(OH)8•64(H2O)
Dana No: 73.02.02c.01 Strunz No: 09.EE.30
Locality:

Notes: