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Johnwalkite

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Johnwalkit
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Johnwalkit
braunes Aggregat von Johnwalkit, Champion Mine, Keystone, Pennington Co., South Dakota, USA; BB ~ 1 mm, analysiert
Copyright: MinTreasure.com (Carsten Slotta); Contribution: openpit
Location: USA/South Dakota/Pennington Co./Keystone District/Keystone/Champion Mine
Mineral: Johnwalkite
Image: 1633547751
License: Usage for Mineralienatlas project only
Johnwalkit

braunes Aggregat von Johnwalkit, Champion Mine, Keystone, Pennington Co., South Dakota, USA; BB 1 mm, analysiert

Copyright: MinTreasure.com (Carsten Slotta)
Contribution: openpit 2021-10-06
Locality: Champion Mine / Keystone / Keystone District / Pennington Co. / South Dakota / USA

Collectors Summary

Hardness (Mohs) 4
Crystal System orthorhombisch, Pb21m

Chemism

Chem­ical formula

K(Mn2+,Fe3+,Fe2+)2(Nb,Ta)(PO4)2O2(H2O,OH)2

Chem­ical com­po­si­tion

Eisen, Mangan, Niob, Tantal, Kalium, Phosphor, Sauerstoff, Wasserstoff

Unit weight: 522.08539078 u; Number of atoms in the formula: 21.5

Info

Empirical formula:

K(Mn0.6Fe0.3Fe0.1)2(Nb0.75Ta0.25)(PO4)2O2((H2O)0.75(OH)0.25)2

Element

Symbol

Weight%

Atoms

Atoms%

Atom weight (u)

Sum weight (u)

Hydrogen

H

0.68

3.5

16.28

1.0079470

3.5278145

Oxygen

O

36.77

12

55.81

15.9994300

191.9931600

Phosphorus

P

11.87

2

9.30

30.9737612

61.9475224

Potassium

K

7.49

1

4.65

39.0983100

39.0983100

Manganese

Mn

12.63

1.2

5.58

54.9380499

65.9256599

Iron

Fe

8.56

0.8

3.72

55.8452000

44.6761600

Niobium

Nb

13.35

0.75

3.49

92.9063820

69.6797865

Tantalum

Ta

8.66

0.25

1.16

180.9479100

45.2369775

Anal­y­sis wt%

Fe2O3 : 12.50, FeO : 3.30, MgO : 0.50, MnO : 14.80, K2O : 8.60, Ta2O5 : 5.10, Nb2O5 : 21.50, P2O5 : 27.30, H2O : 6.50 (Ref: Neues Jahrbuch für Mineralogie, (Monatshefte) 86)

Strunz 9th edi­tion incl. updates

8.DJ.05

8: Phosphate, Arsenate, Vanadate
D: Phosphate, mit weiteren Anionen, mit H2O
J: Mit großen und mittelgroßen [Kationen], (OH, etc.):RO4 = 1:1
05:Olmsteadit-Gruppe

Lapis Clas­sifica­tion

VII/D.39-020

VII: PHOSPHATE, ARSENATE UND VANADATE ("Phosphate" des Registers immer einschließlich isotyper Arsenate und Vanadate!)
D: Wasserhaltige Phosphate, mit fremden Anionen
39: Mittelgroße und sehr große Kationen: Al-Mg und Ca-Na-K

Clas­sifica­tion by Hölzel

8.DI.410

8: PHOSPHATES ARSENATES VANADATES
D: Phosphates (+Anions +Water)
I: C large, V=1(2) - C small-medium, V=2,3,4
4: With other Anions

Dana 8th edi­tion

42.07.11.02

42: Hydrated Phosphates, etc., Containing Hydroxyl or Halogen
07: Hydrated Phosphates, etc., Containing Hydroxyl or Halogen where (AB)5 (XO4)3 Zq · x(H2O)
11: Olmsteadite Group

IMA sta­tus

Anerkannt von der CNMNC

Min­eral sta­tus

anerkanntes Mineral

Optical Properties

max. Birefrin­gence

0.09~

Birefringence chart\! Johnwalkite title=Birefringence chart Johnwalkite

Michel-Levy Color Chart viewed according to the maximum birefringence (at 30μm). Mineral color is not taken into account. Click on the image to enlarge or change thickness.

RI value α / ω / n

1.748

RI value β

1.763

RI value γ / ε

1.84

Ri mean

1.784

2V angle

Biaxial (+) 53°

Crystallography

Crystal Sys­tem

orthorhombisch

Class (H-M)

mm2

Space Group number

26

Space Group

Pb21m

Cell param­e­ters a (Å)

7.516

Cell param­e­ters b (Å)

10.023

Cell param­e­ters c (Å)

6.502

Cell param­e­ters a/b or c/a

0.750

Cell param­e­ters c/b

0.649

Cell param­e­ters α

90°

Cell param­e­ters β

90°

Cell param­e­ters γ

90°

Z

2

Volumne (ų)

489.814

X-Ray Pow­der Diffrac­tion

7.54(30),
6.51(40),
6.01(100),
3.256(30),
3.054(70),
3.005(80),
2.862(70),
2.563(40)

XRD chart Johnwalkite

Calculated from d-spacing and intensity at 0.1541838 nm (Cu)

Crystals 3D

Open larger view

Physical Properties

Hard­ness (Mohs)

4

VHN (Hard­ness Vick­ers)

190 (ungefähre Angabe abgeleitet aus der Mohshärte)

Density (g/cm³)

3.40 (gemessen)

3.54 ( ρ calc. Mineralienatlas )

Preface

Author (Name, Year)

Dunn & Peacor & Sturman & Ramik & Roberts & Nelen, 1986

References

Neues Jahrbuch für Mineralogie, Monatshefte (1986), 115

Other languages

German

Johnwalkit

Spanish

Johnwalkita

English

Johnwalkite

French

Johnwalkite

Russian

Джонуолкит

CNMNC (IMA)-Number

IMA 1985-008

CNMNC symbol

Symbol

Jwk

Automatic Links to external internet sources (Responsibility is with the operator)

German pages

DeWikiPedia - search for: Johnwalkit
Google-Bilder-Suche - search for: Johnwalkit
Mineralienatlas.de (Forum) - search for: Johnwalkit

English pages

Mindat - search for: Johnwalkite
Webmineral - search for:Johnwalkite
Handbook-of-Mineralogy - search for: Johnwalkite
RRUFF - Raman, XRD and other mineral data - search for: Johnwalkite
RRUFF - References and PDF downloads - search for: Johnwalkite
American-Mineralogist-Crystal-Structure-Database - search for: Johnwalkite
Strahlen.org - search for: Johnwalkite

Russian pages

Webmineral.ru - search for: Джонуолкит

Mineral Dealer

German pages

hausen - Mineralgroßhandel - search for: Johnwalkit
Crystal-Treasure.com - search for: Johnwalkit
Bosse - search for: Johnwalkit
Edelsteine Neuburg - Gundolf Fischer - search for: Johnwalkit