Iron meteorite w. silicate inclusions, Octahedrite (IAB-ung, Om)
Found 1924; 25 kg

An iron-rich mass of ~25 kg was found in San Juan County. The meteorite consists primarily of a unique matrix of polycrystalline Fe-Ni metal with the expected minor accessories such as graphite, troilite, and schreibersite. Plessite occupies ~40 vol% of the metallic grains. This dominant octahedral framework is, however, accompanied by irregularly dispersed silicates inclusions representing ~15 vol% of the meteorite. Graphite is found as cliftonite crystals in troilite and kamacite, as rims around silicate grains, and as amorphous carbon. Troilite (shock melted) is found at grain boundaries and as filler between the silicates and graphites. Schreibersite is a late phase which occurs as skeleton crystals and precipitates which have frequently been deposited upon silicate-graphite crystals. Silicates form loose aggregates of pyroxenes (enstatite, diopside) with lesser amounts of Mg-rich olivine and sodic plagioclase (oligoclase). Some weathering has occurred, especially in the troilite.

Four Corners is one of the 47 'ungrouped' IAB iron meteorites which are not clearly associated with any of the various well-defined subgroups within the large IAB iron complex. As of the year 2000, approximately 5 kg was at the National Museum in Washington, but several masses >1 kg are distributed over the world.

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Standard Detailed Gallery Strunz Chemical Elements

Mineral List

10 valid minerals.

Meteorite/Rock Types Recorded

Note: data is currently VERY limited. Please bear with us while we work towards adding this information!

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Alphabetical List Tree Diagram

ⓘ 'Ungrouped IAB iron meteorite'

Detailed Mineral List:

ⓘ Albite

Formula: Na(AlSi₃O₈)

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Albite var. Oligoclase

Formula: (Na,Ca)[Al(Si,Al)Si₂O₈]

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Diopside

Formula: CaMgSi₂O₆

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Enstatite

Formula: Mg₂Si₂O₆

Description: Nearly colorless with Fe/Mg < 0.1

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ 'Fayalite-Forsterite Series'

Description: Mg-rich forsterite

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Graphite

Formula: C

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Graphite var. Cliftonite

Formula: C

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Haxonite

Formula: (Fe,Ni)₂₃C₆

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ 'Limonite'

Description: A purplish weather product of shock-melted troilite.

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Native Iron

Formula: Fe

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Native Iron var. Kamacite

Formula: (Fe,Ni)

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Native Iron var. Martensite

Formula: Fe

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Pentlandite

Formula: (Ni_xFe_y)_Σ9S₈

Description: Converted troilite

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ 'Plessite'

References:

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Schreibersite

Formula: (Fe,Ni)₃P

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Taenite

Formula: (Fe,Ni)

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

ⓘ Troilite

Formula: FeS

References:

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Native Iron	1.AE.05	Fe
ⓘ	var. Kamacite	1.AE.05	(Fe,Ni)
ⓘ	var. Martensite	1.AE.05	Fe
ⓘ	Taenite	1.AE.10	(Fe,Ni)
ⓘ	Haxonite	1.BA.10	(Fe,Ni)₂₃C₆
ⓘ	Schreibersite	1.BD.05	(Fe,Ni)₃P
ⓘ	Graphite	1.CB.05a	C
ⓘ	var. Cliftonite	1.CB.05a	C
Group 2 - Sulphides and Sulfosalts
ⓘ	Pentlandite	2.BB.15	(Ni_xFe_y)_Σ9S₈
ⓘ	Troilite	2.CC.10	FeS
Group 9 - Silicates
ⓘ	Enstatite	9.DA.05	Mg₂Si₂O₆
ⓘ	Diopside	9.DA.15	CaMgSi₂O₆
ⓘ	Albite	9.FA.35	Na(AlSi₃O₈)
ⓘ	var. Oligoclase	9.FA.35	(Na,Ca)[Al(Si,Al)Si₂O₈]
Unclassified
ⓘ	'Limonite'	-
ⓘ	'Fayalite-Forsterite Series'	-
ⓘ	'Plessite'	-

List of minerals for each chemical element

C	Carbon
C	ⓘ Graphite	C
C	ⓘ Haxonite	(Fe,Ni)₂₃C₆
C	ⓘ Graphite var. Cliftonite	C
O	Oxygen
O	ⓘ Albite	Na(AlSi₃O₈)
O	ⓘ Diopside	CaMgSi₂O₆
O	ⓘ Enstatite	Mg₂Si₂O₆
O	ⓘ Albite var. Oligoclase	(Na,Ca)[Al(Si,Al)Si₂O₈]
O	ⓘ Fayalite-Forsterite Series
Na	Sodium
Na	ⓘ Albite	Na(AlSi₃O₈)
Na	ⓘ Albite var. Oligoclase	(Na,Ca)[Al(Si,Al)Si₂O₈]
Mg	Magnesium
Mg	ⓘ Diopside	CaMgSi₂O₆
Mg	ⓘ Enstatite	Mg₂Si₂O₆
Mg	ⓘ Fayalite-Forsterite Series
Al	Aluminium
Al	ⓘ Albite	Na(AlSi₃O₈)
Al	ⓘ Albite var. Oligoclase	(Na,Ca)[Al(Si,Al)Si₂O₈]
Si	Silicon
Si	ⓘ Albite	Na(AlSi₃O₈)
Si	ⓘ Diopside	CaMgSi₂O₆
Si	ⓘ Enstatite	Mg₂Si₂O₆
Si	ⓘ Albite var. Oligoclase	(Na,Ca)[Al(Si,Al)Si₂O₈]
Si	ⓘ Fayalite-Forsterite Series
P	Phosphorus
P	ⓘ Schreibersite	(Fe,Ni)₃P
S	Sulfur
S	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
S	ⓘ Troilite	FeS
Ca	Calcium
Ca	ⓘ Diopside	CaMgSi₂O₆
Ca	ⓘ Albite var. Oligoclase	(Na,Ca)[Al(Si,Al)Si₂O₈]
Fe	Iron
Fe	ⓘ Haxonite	(Fe,Ni)₂₃C₆
Fe	ⓘ Native Iron	Fe
Fe	ⓘ Native Iron var. Kamacite	(Fe,Ni)
Fe	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Fe	ⓘ Schreibersite	(Fe,Ni)₃P
Fe	ⓘ Taenite	(Fe,Ni)
Fe	ⓘ Troilite	FeS
Fe	ⓘ Fayalite-Forsterite Series
Fe	ⓘ Native Iron var. Martensite	Fe
Ni	Nickel
Ni	ⓘ Haxonite	(Fe,Ni)₂₃C₆
Ni	ⓘ Native Iron var. Kamacite	(Fe,Ni)
Ni	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Ni	ⓘ Schreibersite	(Fe,Ni)₃P
Ni	ⓘ Taenite	(Fe,Ni)

Other Regions, Features and Areas containing this locality

North AmericaContinent

North America PlateTectonic Plate

USA

Arizona & Utah
- Apache; Navajo and San Juan Cos.
  - Colorado Plateau
    - Hopi-Navajo Indian Reservations
Colorado PlateauPlateau
⭔Navajo Nation Indian ReservationReservation
New Mexico
- San Juan County
  - ⭔Navajo Nation ReservationReservation

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

www.encyclopedia-of-meteorites.com (n.d.) http://www.encyclopedia-of-meteorites.com/test/fourcorners.jpg

evols.library.manoa.hawaii.edu (n.d.) http://evols.library.manoa.hawaii.edu/bitstream/handle/10524/35677/vol2-Fo-Ga(LO)pdf#page=7

Ramdohr, Paul (1972) The Opaque Minerals in Stony Meteorites. De Gruyter. doi:10.1515/9783112651025

Buchwald, Vagn F. (1975) Handbook of Iron Meteorites - Their History, Distribution, Composition and Structure. University of California Press.

Grady, Monica (2000) Catalogue of Meteorites (5th ed.). Cambridge University Press.

www.lpi.usra.edu (n.d.) http://www.lpi.usra.edu/meteor/metbull.php

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Four Corners meteorite, San Juan County, Utah, USAiRegional Level TypesFour Corners meteoriteMeteorite Fall Location San Juan CountyCounty UtahState USACountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }

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Detailed Mineral List:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Other Regions, Features and Areas containing this locality

References

Four Corners meteorite, San Juan County, Utah, USA i
Regional Level Types
Four Corners meteorite Meteorite Fall Location
San Juan County County
Utah State
USA Country