Mining concession no. 362 Casas Novas (Fe), registered on 30-04-1903.

The Casas Novas gold deposit is located in the Escoural Gold District of the Ossa Morena Zone (OMZ, SW Iberia) and consists of an orogenic gold system characterized by structurally controlled mesothermal lodes, which are related to a major shear zone. The mineralization shows evidence of two distinct metallogenic phases during regional metamorphism: (i) an early higher-temperature stage marked by Co-Ni-rich loellingite hosting Au-(Ag) alloys accompanied by pyrrhotite, and (ii) a later low-temperature stage with arsenopyrite, gold, maldonite and Bi-Te sulfosalts. Detailed textural analysis documents the evolution from initial Au-Ag alloys enclosed in Co-Ni-rich loellingite to subsequent Au-Bi-Te phases and newly formed arsenopyrite. The results show the thermal and chemical changes in the system, demonstrating the importance of fluid–rock interactions in the redox conditions, which became more oxidized, controlling the gold deposition.

The iron mines of Montemor.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.

ⓘ Gold

ⓘ Iron

Mineral List

23 valid minerals.

Rock Types Recorded

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

ⓘ Albite

Formula: Na(AlSi₃O₈)

References:

São Pedro, Diogo; Roseiro, José; Pedro, Jorge; Mirão, José; Fuertes-Fuente, Mercedes; Nogueira, Pedro (2026) Decoding Orogenic Gold Mineralization Types During Regional Metamorphic Evolution: Detailed Textural Analysis from a Deposit in the Ossa-Morena Zone (SW Iberia). Minerals, 16 (7). doi:10.3390/min16070709

ⓘ Arsenopyrite

Formula: FeAsS

References:

ⓘ 'Biotite'

Formula: K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂

References:

ⓘ Calcite

Formula: CaCO₃

References:

ⓘ 'Calcium Amphibole Subgroup'

Formula: A_nCa₂(C²⁺_5-mC³⁺_m)(Si_8-(n+m)Al_(n+m))W₂

References:

ⓘ 'Calcium Amphibole Subgroup var. Hornblende'

Formula: A_nCa₂(Z²⁺_5-mZ³⁺_m)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂

References:

ⓘ Chalcopyrite

Formula: CuFeS₂

References:

ⓘ 'Chlorite Group'

References:

ⓘ Cobaltite

Formula: CoAsS

References:

ⓘ Epidote

Formula: (CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)

References:

ⓘ 'Feldspar Group'

References:

ⓘ Galena

Formula: PbS

References:

ⓘ Glaucodot

Formula: (Co_0.50Fe_0.50)AsS

References:

ⓘ Hedleyite

Formula: Bi₇Te₃

References:

ⓘ Ilmenite

Formula: Fe²⁺TiO₃

References:

ⓘ Kaolinite

Formula: Al₂(Si₂O₅)(OH)₄

References:

ⓘ 'K Feldspar'

References:

ⓘ Löllingite

Formula: FeAs₂

References:

ⓘ Maldonite

Formula: Au₂Bi

References:

ⓘ Muscovite

Formula: KAl₂(AlSi₃O₁₀)(OH)₂

References:

ⓘ Muscovite var. Sericite

Formula: KAl₂(AlSi₃O₁₀)(OH)₂

References:

ⓘ Native Bismuth

Formula: Bi

References:

ⓘ Native Gold

Formula: Au

References:

ⓘ Pentlandite

Formula: (Ni_xFe_y)_Σ9S₈

References:

ⓘ 'Plagioclase'

Formula: (Na,Ca)[(Si,Al)AlSi₂]O₈

References:

ⓘ Pyrite

Formula: FeS₂

References:

ⓘ Pyrrhotite

Formula: Fe_1-xS

References:

ⓘ Quartz

Formula: SiO₂

References:

ⓘ Rutile

Formula: TiO₂

References:

ⓘ Sillimanite

Formula: Al₂(SiO₄)O

References:

ⓘ 'Tourmaline'

Formula: AD₃G₆(T₆O₁₈)(BO₃)₃X₃Z

References:

ⓘ Tremolite

Formula: ◻Ca₂Mg₅(Si₈O₂₂)(OH)₂

References:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Native Gold	1.AA.05	Au
ⓘ	Native Bismuth	1.CA.05	Bi
Group 2 - Sulphides and Sulfosalts
ⓘ	Maldonite	2.AA.40	Au₂Bi
ⓘ	Pentlandite	2.BB.15	(Ni_xFe_y)_Σ9S₈
ⓘ	Chalcopyrite	2.CB.10a	CuFeS₂
ⓘ	Pyrrhotite	2.CC.10	Fe_1-xS
ⓘ	Galena	2.CD.10	PbS
ⓘ	Hedleyite	2.DC.05	Bi₇Te₃
ⓘ	Pyrite	2.EB.05a	FeS₂
ⓘ	Glaucodot	2.EB.10c	(Co_0.50Fe_0.50)AsS
ⓘ	Löllingite	2.EB.15a	FeAs₂
ⓘ	Arsenopyrite	2.EB.20	FeAsS
ⓘ	Cobaltite	2.EB.25	CoAsS
Group 4 - Oxides and Hydroxides
ⓘ	Ilmenite	4.CB.05	Fe²⁺TiO₃
ⓘ	Quartz	4.DA.05	SiO₂
ⓘ	Rutile	4.DB.05	TiO₂
Group 5 - Nitrates and Carbonates
ⓘ	Calcite	5.AB.05	CaCO₃
Group 9 - Silicates
ⓘ	Sillimanite	9.AF.05	Al₂(SiO₄)O
ⓘ	Epidote	9.BG.05a	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
ⓘ	Tremolite	9.DE.10	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
ⓘ	Muscovite	9.EC.15	KAl₂(AlSi₃O₁₀)(OH)₂
ⓘ	var. Sericite	9.EC.15	KAl₂(AlSi₃O₁₀)(OH)₂
ⓘ	Kaolinite	9.ED.05	Al₂(Si₂O₅)(OH)₄
ⓘ	Albite	9.FA.35	Na(AlSi₃O₈)
Unclassified
ⓘ	'Biotite'	-	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
ⓘ	'Chlorite Group'	-
ⓘ	'Feldspar Group'	-
ⓘ	'Calcium Amphibole Subgroup var. Hornblende'	-	A_nCa₂(Z²⁺_5-mZ³⁺_m)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
ⓘ	'Tourmaline'	-	AD₃G₆(T₆O₁₈)(BO₃)₃X₃Z
ⓘ	'Plagioclase'	-	(Na,Ca)[(Si,Al)AlSi₂]O₈
ⓘ	'K Feldspar'	-
ⓘ	'Calcium Amphibole Subgroup'	-	A_nCa₂(C²⁺_5-mC³⁺_m)(Si_8-(n+m)Al_(n+m))W₂

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
H	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
H	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
H	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
H	ⓘ Muscovite	KAl₂(AlSi₃O₁₀)(OH)₂
H	ⓘ Tremolite	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
H	ⓘ Muscovite var. Sericite	KAl₂(AlSi₃O₁₀)(OH)₂
B	Boron
B	ⓘ Tourmaline	AD₃G₆(T₆O₁₈)(BO₃)₃X₃Z
C	Carbon
C	ⓘ Calcite	CaCO₃
O	Oxygen
O	ⓘ Albite	Na(AlSi₃O₈)
O	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
O	ⓘ Calcite	CaCO₃
O	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
O	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
O	ⓘ Ilmenite	Fe²⁺TiO₃
O	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
O	ⓘ Muscovite	KAl₂(AlSi₃O₁₀)(OH)₂
O	ⓘ Quartz	SiO₂
O	ⓘ Rutile	TiO₂
O	ⓘ Sillimanite	Al₂(SiO₄)O
O	ⓘ Tourmaline	AD₃G₆(T₆O₁₈)(BO₃)₃X₃Z
O	ⓘ Tremolite	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
O	ⓘ Muscovite var. Sericite	KAl₂(AlSi₃O₁₀)(OH)₂
O	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
F	Fluorine
F	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
F	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
Na	Sodium
Na	ⓘ Albite	Na(AlSi₃O₈)
Na	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Mg	Magnesium
Mg	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Mg	ⓘ Tremolite	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
Al	Aluminium
Al	ⓘ Albite	Na(AlSi₃O₈)
Al	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Al	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Al	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
Al	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
Al	ⓘ Muscovite	KAl₂(AlSi₃O₁₀)(OH)₂
Al	ⓘ Sillimanite	Al₂(SiO₄)O
Al	ⓘ Muscovite var. Sericite	KAl₂(AlSi₃O₁₀)(OH)₂
Al	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Al	ⓘ Calcium Amphibole Subgroup	A_nCa₂(C²⁺_5-mC_m³⁺)(Si_8-(n+m)Al_(n+m))W₂
Si	Silicon
Si	ⓘ Albite	Na(AlSi₃O₈)
Si	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Si	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Si	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
Si	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
Si	ⓘ Muscovite	KAl₂(AlSi₃O₁₀)(OH)₂
Si	ⓘ Quartz	SiO₂
Si	ⓘ Sillimanite	Al₂(SiO₄)O
Si	ⓘ Tremolite	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
Si	ⓘ Muscovite var. Sericite	KAl₂(AlSi₃O₁₀)(OH)₂
Si	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Si	ⓘ Calcium Amphibole Subgroup	A_nCa₂(C²⁺_5-mC_m³⁺)(Si_8-(n+m)Al_(n+m))W₂
S	Sulfur
S	ⓘ Arsenopyrite	FeAsS
S	ⓘ Chalcopyrite	CuFeS₂
S	ⓘ Cobaltite	CoAsS
S	ⓘ Galena	PbS
S	ⓘ Glaucodot	(Co_0.50Fe_0.50)AsS
S	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
S	ⓘ Pyrite	FeS₂
S	ⓘ Pyrrhotite	Fe_1-xS
Cl	Chlorine
Cl	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
K	Potassium
K	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
K	ⓘ Muscovite	KAl₂(AlSi₃O₁₀)(OH)₂
K	ⓘ Muscovite var. Sericite	KAl₂(AlSi₃O₁₀)(OH)₂
Ca	Calcium
Ca	ⓘ Calcite	CaCO₃
Ca	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Ca	ⓘ Calcium Amphibole Subgroup var. Hornblende	A_nCa₂(Z²⁺_5-mZ_m³⁺)(Si_8-(n+m)Al_(n+m))(OH,F,Cl)₂
Ca	ⓘ Tremolite	◻Ca₂Mg₅(Si₈O₂₂)(OH)₂
Ca	ⓘ Plagioclase	(Na,Ca)[(Si,Al)AlSi₂]O₈
Ca	ⓘ Calcium Amphibole Subgroup	A_nCa₂(C²⁺_5-mC_m³⁺)(Si_8-(n+m)Al_(n+m))W₂
Ti	Titanium
Ti	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Ti	ⓘ Ilmenite	Fe²⁺TiO₃
Ti	ⓘ Rutile	TiO₂
Fe	Iron
Fe	ⓘ Arsenopyrite	FeAsS
Fe	ⓘ Biotite	K(Fe²⁺/Mg)₂(Al/Fe³⁺/Mg/Ti)([Si/Al/Fe]₂Si₂O₁₀)(OH/F)₂
Fe	ⓘ Chalcopyrite	CuFeS₂
Fe	ⓘ Epidote	(CaCa)(AlAlFe³⁺)O[Si₂O₇][SiO₄](OH)
Fe	ⓘ Glaucodot	(Co_0.50Fe_0.50)AsS
Fe	ⓘ Ilmenite	Fe²⁺TiO₃
Fe	ⓘ Löllingite	FeAs₂
Fe	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Fe	ⓘ Pyrite	FeS₂
Fe	ⓘ Pyrrhotite	Fe_1-xS
Co	Cobalt
Co	ⓘ Cobaltite	CoAsS
Co	ⓘ Glaucodot	(Co_0.50Fe_0.50)AsS
Ni	Nickel
Ni	ⓘ Pentlandite	(Ni_xFe_y)_Σ9S₈
Cu	Copper
Cu	ⓘ Chalcopyrite	CuFeS₂
As	Arsenic
As	ⓘ Arsenopyrite	FeAsS
As	ⓘ Cobaltite	CoAsS
As	ⓘ Glaucodot	(Co_0.50Fe_0.50)AsS
As	ⓘ Löllingite	FeAs₂
Te	Tellurium
Te	ⓘ Hedleyite	Bi₇Te₃
Au	Gold
Au	ⓘ Native Gold	Au
Au	ⓘ Maldonite	Au₂Bi
Pb	Lead
Pb	ⓘ Galena	PbS
Bi	Bismuth
Bi	ⓘ Native Bismuth	Bi
Bi	ⓘ Hedleyite	Bi₇Te₃
Bi	ⓘ Maldonite	Au₂Bi

Other Regions, Features and Areas containing this locality

Eurasian PlateTectonic Plate

Ossa-Morena ZoneVolcanic Arc

EuropeContinent

Iberian PeninsulaPeninsula

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

Minas de Ferro de Montemor-o-Novo. Direccao Geral de Minas e Servicos Geologicos - Servico de Fomento Miniero - 1949 - Por Adalberto de Andrade-Joao Martins da Silva-Carlos dos Reis Arruda-Jose Coelho da Silva a Gameiro.

[1]São Pedro, Diogo; Roseiro, José; Pedro, Jorge; Mirão, José; Fuertes-Fuente, Mercedes; Nogueira, Pedro (2026) Decoding Orogenic Gold Mineralization Types During Regional Metamorphic Evolution: Detailed Textural Analysis from a Deposit in the Ossa-Morena Zone (SW Iberia). Minerals, 16 (7). doi:10.3390/min16070709

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