Named in 1968 by Peter H. Nixon and George Hornung in honor of Oleg Von Knorring [1915 Novgorod, Russia - 1994 Leeds, England, UK], a research geochemist at University of Helsinki, Finland and later Professor of Mineralogy, University of Leeds, England and associated with the Research Institute of African Geology. He specialized in granite pegmatite mineralogy and named: bertossaite, burangite, cerotungstite, holdawayite, karibibite, kennedyite, mboziite, mpororoite, namibite, rankamaite, waylandite, and westgrenite.

Type Locality:

ⓘ Kao Mine, Butha-Buthe District, Lesotho

Garnet Group. Knorringite-Pyrope Series.

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Unique IdentifiersHide

Mindat ID:

2229

Long-form identifier:

mindat:1:1:2229:9

GUID
(UUID V4):

c5ce83cc-4438-4148-a84f-fca2cbd34f28

IMA Classification of KnorringiteHide

IMA status:

Approved

Approval year:

1968

First published:

1968

Type description reference:

Nixon, P.H., Hornung, G. (1968): A new chromium garnet end member, knorringite, from Kimberlite. American Mineralogist 53, 1833-1840

Classification of KnorringiteHide

Strunz-mindat (2024):

9.AD.25

9 : SILICATES (Germanates)
A : Nesosilicates
D : Nesosilicates without additional anions; cations in [6] and/or greater coordination

Dana 8th ed.:

51.4.3a.4

51 : NESOSILICATES Insular SiO₄ Groups Only
4 : Insular SiO₄ Groups Only with cations in [6] and >[6] coordination

Hey's CIM Ref.:

14.15.3

14 : Silicates not Containing Aluminum
15 : Silicates of Cr

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Symbol	Source	Reference
Krr	IMA–CNMNC	Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of KnorringiteHide

Lustre:

Vitreous

Transparency:

Translucent

Colour:

Green, blue

Streak:

White

Hardness:

6 - 7 on Mohs scale

Density:

3.756 g/cm³ (Measured) 3.852 g/cm³ (Calculated)

Optical Data of KnorringiteHide

Type:

Isotropic

RI values:

n = 1.803

Birefringence:

Isotropic minerals have no birefringence

Surface Relief:

Very High

Chemistry of KnorringiteHide

Mindat Formula:

Mg₃Cr₂(SiO₄)₃

Elements listed:

Cr, Mg, O, Si - search for minerals with similar chemistry

Common Impurities:

Ti,Al,Fe,Mn,Ca

Crystallography of KnorringiteHide

Crystal System:

Isometric

Class (H-M):

m3m (4/m 3 2/m) - Hexoctahedral

Space Group:

Ia3d

Setting:

Ia3d

Cell Parameters:

a = 11.65 Å

Unit Cell V:

1,581.17 Å³ (Calculated from Unit Cell)

Crystal StructureHide

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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure

ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0004999	Knorringite	Juhin A, Morin G, Elkaim E, Frost D J, Fialin M, Juillot F, Calas G (2010) Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3 American Mineralogist 95 59-63		2010	synthetic	0	293

CIF Raw Data - click here to close

data_global
_chemical_name_mineral 'Knorringite'
loop_
_publ_author_name
'Juhin A'
'Morin G'
'Elkaim E'
'Frost D J'
'Fialin M'
'Juillot F'
'Calas G'
_journal_name_full 'American Mineralogist'
_journal_volume 95 
_journal_year 2010
_journal_page_first 59
_journal_page_last 63
_publ_section_title
;
 Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
;
_database_code_amcsd 0004999
_chemical_compound_source 'Synthetic'
_chemical_formula_sum 'Cr1.68 Mg3.16 Si3.16 O12'
_cell_length_a 11.5935
_cell_length_b 11.5935
_cell_length_c 11.5935
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 1558.273
_exptl_crystal_density_diffrn      3.793
_symmetry_space_group_name_H-M 'I a -3 d'
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  '3/4+y,3/4+x,3/4+z'
  '1/4-x,1/4-z,1/4-y'
  '3/4-x,3/4-z,3/4-y'
  '1/4+z,1/4+y,1/4+x'
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  '1/4-x,1/4+z,3/4-y'
  '3/4+z,3/4-y,1/4+x'
  '1/4+z,1/4-y,3/4+x'
  '3/4-y,3/4+x,1/4-z'
  '1/4-y,1/4+x,3/4-z'
  '3/4+x,3/4-z,1/4+y'
  '1/4+x,1/4-z,3/4+y'
  '3/4-z,3/4+y,1/4-x'
  '1/4-z,1/4+y,3/4-x'
  '3/4+y,3/4-x,1/4+z'
  '1/4+y,1/4-x,3/4+z'
  '1/4-x,3/4-z,3/4+y'
  '3/4-x,1/4-z,1/4+y'
  '1/4+z,3/4+y,3/4-x'
  '3/4+z,1/4+y,1/4-x'
  '1/4-y,3/4-x,3/4+z'
  '3/4-y,1/4-x,1/4+z'
  '1/4+x,3/4+z,3/4-y'
  '3/4+x,1/4+z,1/4-y'
  '1/4-z,3/4-y,3/4+x'
  '3/4-z,1/4-y,1/4+x'
  '1/4+y,3/4+x,3/4-z'
  '3/4+y,1/4+x,1/4-z'
  '-z,-x,-y'
  '1/2-z,1/2-x,1/2-y'
  'y,z,x'
  '1/2+y,1/2+z,1/2+x'
  '-x,-y,-z'
  '1/2-x,1/2-y,1/2-z'
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  '1/2+z,1/2+x,1/2+y'
  '-y,-z,-x'
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loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
CrY   0.00000   0.00000   0.00000   0.84000   0.00431
MgY   0.00000   0.00000   0.00000   0.08000   0.00431
SiY   0.00000   0.00000   0.00000   0.08000   0.00431
MgX   0.12500   0.00000   0.25000   1.00000   0.01418
SiZ   0.37500   0.00000   0.25000   1.00000   0.00583
O   0.03480   0.05160   0.65710   1.00000   0.01368

X-Ray Powder DiffractionHide

Powder Diffraction Data:

d-spacing	Intensity
2.92 Å	(100)
2.61 Å	(100)
2.382 Å	(80)
1.560 Å	(80)
2.489 Å	(60)
2.288 Å	(60)
1.894 Å	(60)

Comments:

Kao kimberlite pipe, Lesotho. Data from the type description.

Geological EnvironmentHide

Paragenetic Mode(s):

Paragenetic Mode	Earliest Age (Ga)
Stage 4b: Highly evolved igneous rocks	>3.0
36 : Carbonatites, kimberlites, and related igneous rocks

Type Occurrence of KnorringiteHide

Type Locality:

ⓘ Kao Mine, Butha-Buthe District, Lesotho

General Appearance of Type Material:

Massive and as minute grains.

Place of Conservation of Type Material:

No designated type material.

Geological Setting of Type Material:

Ultramafic kimberlite nodules.

Associated Minerals at Type Locality:

Zircon	Rutile	Perovskite	Omphacite	Olivine Group
Ilmenite	Enstatite	Enstatite	Enstatite	Diamond
Chrome-Spinel (of Dana)

Reference:

Nixon, P.H., Hornung, G. (1968): A new chromium garnet end member, knorringite, from Kimberlite. American Mineralogist 53, 1833-1840

Synonyms of KnorringiteHide

IMA1968-010

Other Language Names for KnorringiteHide

German:Knorringit

Spanish:Knorringita

Relationship of Knorringite to other SpeciesHide

Member of:

Garnet Group > Garnet Supergroup

Other Members of this group:

Almandine	Fe²⁺₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Andradite	Ca₃Fe³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Blythite	Mn²⁺₃Mn³⁺₂[SiO₄]₃
Calderite	Mn²⁺₃Fe³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Eringaite	Ca₃Sc₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Goldmanite	Ca₃V³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Grossular	Ca₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Khoharite	Mg₃Fe³⁺₂(SiO₄)₃
Majorite	Mg₃(MgSi)(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Menzerite-(Y)	(Y₂Ca)Mg₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Momoiite	Mn²⁺₃V³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Morimotoite	Ca₃(TiFe²⁺)(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Pyrope	Mg₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Skiagite	Fe²⁺₃Fe³⁺₂[SiO₄]₃
Spessartine	Mn²⁺₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
Uvarovite	Ca₃Cr₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d

Forms a series with:

Pyrope

Knorringite-Pyrope Series

Related Minerals - Strunz-mindat Grouping Hide

9.AD.	Adrianite	Ca₁₂(Al₄Mg₃Si₇)O₃₂Cl₆	Iso. 4 3m : I4 3d
9.AD.05	Larnite	Ca₂SiO₄	Mon. 2/m
9.AD.10	Calcio-olivine	Ca₂SiO₄	Orth. mmm (2/m 2/m 2/m)
9.AD.15	Merwinite	Ca₃Mg(SiO₄)₂	Mon. 2/m : P2₁/b
9.AD.20	Bredigite	Ca₇Mg(SiO₄)₄	Orth. mm2 : Pnn2
9.AD.25	Andradite	Ca₃Fe³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Almandine	Fe²⁺₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Calderite	Mn²⁺₃Fe³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Goldmanite	Ca₃V³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Grossular	Ca₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Henritermierite	Ca₃Mn³⁺₂(SiO₄)₂[◻(OH)₄]	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/acd
9.AD.25	Kimzeyite	Ca₃Zr₂(SiO₄)(AlO₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Majorite	Mg₃(MgSi)(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Morimotoite	Ca₃(TiFe²⁺)(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Pyrope	Mg₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Schorlomite	Ca₃Ti₂(SiO₄)(Fe³⁺O₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Spessartine	Mn²⁺₃Al₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Uvarovite	Ca₃Cr₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Wadalite	(Ca,Mg)₆(Al,Fe³⁺)₄((Si,Al)O₄)₃O₄Cl₃	Iso. 4 3m : I4 3d
9.AD.25 va	Hydrougrandite	(Ca,Mg,Fe²⁺)₃(Fe³⁺,Al)₂[(OH)₄(SiO₄)₂]	Iso.
9.AD.25 va	Yamatoite	(Mn²⁺,Ca)₃(V³⁺,Al)₂(SiO₄)₃	Iso.
9.AD.25	Holtstamite	Ca₃Al₂(SiO₄)₂[◻(OH)₄]	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/acd
9.AD.25	Khoharite	Mg₃Fe³⁺₂(SiO₄)₃
9.AD.25	Kerimasite	Ca₃Zr₂(SiO₄)(Fe³⁺O₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Toturite	Ca₃Sn₂(SiO₄)(Fe³⁺O₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Momoiite	Mn²⁺₃V³⁺₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Eringaite	Ca₃Sc₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Irinarassite	Ca₃Sn₂(SiO₄)(AlO₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Menzerite-(Y)	(Y₂Ca)Mg₂(SiO₄)₃	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	Eltyubyuite	Ca₁₂Fe³⁺₁₀Si₄O₃₂Cl₆	Iso. 4 3m : I4 3d
9.AD.25	Blythite	Mn²⁺₃Mn³⁺₂[SiO₄]₃
9.AD.25	Skiagite	Fe²⁺₃Fe³⁺₂[SiO₄]₃
9.AD.25	Hutcheonite	Ca₃Ti₂(SiO₄)(AlO₄)₂	Iso. m3m (4/m 3 2/m) : Ia3d
9.AD.25	UM1984-37-SiO:CrMn	Mn²⁺₃Cr³⁺₂(SiO₄)₃
9.AD.25	Rubinite	Ca₃Ti³⁺₂Si₃O₁₂	Iso.
9.AD.25	Nikmelnikovite	Ca₁₂(Fe²⁺Fe³⁺₃Al₃◻)[SiO₄]₆[◻(OH)₄]₅◻₄	Trig. 3 : R3
9.AD.30 va	Auerlite	near Th(Si,P)O₄
9.AD.30	Coffinite	U(SiO₄) · nH₂O	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
9.AD.30	Hafnon	HfSiO₄	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
9.AD.30	Thorite	Th(SiO₄)	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
9.AD.30	Zircon	Zr(SiO₄)	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
9.AD.30	Stetindite-(Ce)	Ce(SiO₄)	Tet. 4/mmm (4/m 2/m 2/m) : I4₁/amd
9.AD.35	Huttonite	ThSiO₄	Mon. 2/m
9.AD.35	Tombarthite-(Y)	Y₄(Si,H₄)₄O_12-x(OH)_4+2x	Mon.
9.AD.40	Eulytine	Bi₄(SiO₄)₃	Iso. 4 3m : I4 3d
9.AD.45	Reidite	ZrSiO₄	Tet. 4/m : I4₁/a
9.AD.55	Jeffbenite	Mg₃Al₂Si₃O₁₂	Tet. 4 2m : I4 2d

Other InformationHide

Health Risks:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for KnorringiteHide

mindat.org URL:

https://www.mindat.org/min-2229.html
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Raman and XRD data at RRUFF project

References and PDF downloads at RRUFF project

American Mineralogist Crystal Structure Database

Handbook of Mineralogy page PDF

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References for KnorringiteHide

Reference List:

Nixon, P.H., Hornung, G. (1968): A new chromium garnet end member, knorringite, from Kimberlite. American Mineralogist, 53, 1833-1840.

Nixon, P.H., Hornung, G. (1968): A new chromium garnet end member, knorringite, from Kimberlite. American Mineralogist 53, 1833-1840

Ringwood, A.E. (1977): Synthesis of pyrope-knorringite solid solution series. Earth and Planetary Science Letters, 36, 443-448.

Juhin, A., Morin, G., Elkaim, E., Frost, D.J., Fialin, M., Juillot, F., Calas, G. (2010): Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3. American Mineralogist, 95, 59-63.

Bindi, L., Sirotkina, E.A., Bobrov, A.V., Irifune, T. (2014): Chromium solubility in perovskite at high pressure: The structure of (Mg1-xCrx)(Si1-xCrx)O3 (with x = 0.07) synthesized at 23 GPa and 1600 °C. American Mineralogist, 99, 866-869.

(2023) Knorringite. Handbook of Mineralogy. Mineralogical Society of America

Localities for KnorringiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the

symbol to view information about a locality. The

symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed.

- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality.

- Good crystals or important locality for species.

- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). ~~Struck out~~ - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.


Antarctica
Eastern Antarctica Buckley Island quadrangle Lewis Cliff ⓘ Lewis Cliff 88774 meteorite	Goodrich et al. (2001)

Canada
Québec Abitibi-Témiscamingue La Vallée-de-l'Or RCM Réservoir-Dozois ⓘ Cabonga Reservoir	Olivier Langelier Collection

Lesotho (TL)
Butha-Buthe District ⓘ Kao Mine (TL)	AmMin 53 (1968)

USA
California Nevada County Washington Mining District (Omega Mining District) Washington ⓘ Red Ledge Mine	Mineralogical Society of America - ...

Knorringite