Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Cortlandt Township, Westchester County, New York, USAi
Regional Level Types
Cortlandt TownshipTownship
Westchester CountyCounty
New YorkState
USACountry

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Largest Settlements:
PlacePopulation
Croton-on-Hudson8,269 (2017)
Montrose2,731 (2017)
Crompond2,292 (2017)
Buchanan2,268 (2017)
Verplanck1,729 (2017)
Crugers1,534 (2017)
Mindat Locality ID:
16852
Long-form identifier:
mindat:1:2:16852:9
GUID (UUID V4):
0


[Note that the city of Peekskill is no longer part of Cortlandt.]

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List

Mineral list contains entries from the region specified including sub-localities

27 valid minerals.

Rock Types Recorded


Rock list contains entries from the region specified including sub-localities

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

Actinolite
Formula: ◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Albite
Formula: Na(AlSi3O8)
Albite var. Oligoclase
Formula: (Na,Ca)[Al(Si,Al)Si2O8]
Almandine
Formula: Fe2+3Al2(SiO4)3
'Amphibole Supergroup'
Formula: AB2C5(T8O22)W2
Analcime
Formula: Na(AlSi2O6) · H2O
'Apatite'
Formula: Ca5(PO4)3A
'Biotite'
Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Calcite
Formula: CaCO3
Chalcopyrite
Formula: CuFeS2
'Chlorite Group'
'Chrysolite'
Chrysotile
Formula: Mg3(Si2O5)(OH)4
Cordierite
Formula: Mg2Al4Si5O18
Corundum
Formula: Al2O3
Epidote
Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
'Garnet Group'
Formula: X3Z2(SiO4)3
Hercynite
Formula: Fe2+Al2O4
'Högbomite Group'
Kyanite
Formula: Al2(SiO4)O
'Limonite'
Magnesiohögbomite-6N6S
Formula: [(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
Magnesio-riebeckite
Formula: ◻Na2(Mg3Fe3+2)(Si8O22)(OH)2
Magnetite
Formula: Fe2+Fe3+2O4
Magnetite var. Titanium-bearing Magnetite
Formula: Fe2+(Fe3+,Ti)2O4
Molybdenite
Formula: MoS2
Muscovite
Formula: KAl2(AlSi3O10)(OH)2
Natrolite
Formula: Na2Al2Si3O10 · 2H2O
Opal
Formula: SiO2 · nH2O
Opal var. Opal-AN
Formula: SiO2 · nH2O
'Orthopyroxene Subgroup'
Phlogopite
Formula: KMg3(AlSi3O10)(OH)2
Pyrite
Formula: FeS2
'Pyroxene Group'
Formula: ADSi2O6
Pyrrhotite
Formula: Fe1-xS
Quartz
Formula: SiO2
Sapphirine
Formula: Mg4(Mg3Al9)O4[Si3Al9O36]
Sillimanite
Formula: Al2(SiO4)O
Spinel
Formula: MgAl2O4
Spinel var. Ceylonite
Formula: MgAl2O4
Staurolite
Formula: Fe2+2Al9Si4O23(OH)
'Stilbite Subgroup'
Formula: M6-7[Al8-9Si27-28O72] · nH2O
'Tourmaline'
Formula: AD3G6(T6O18)(BO3)3X3Z

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Chalcopyrite2.CB.10aCuFeS2
Pyrrhotite2.CC.10Fe1-xS
Molybdenite2.EA.30MoS2
Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
Hercynite4.BB.05Fe2+Al2O4
Magnetite4.BB.05Fe2+Fe3+2O4
Spinel4.BB.05MgAl2O4
Magnetite
var. Titanium-bearing Magnetite
4.BB.05Fe2+(Fe3+,Ti)2O4
Spinel
var. Ceylonite
4.BB.05MgAl2O4
Corundum4.CB.05Al2O3
Magnesiohögbomite-6N6S4.CB.20[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
Quartz4.DA.05SiO2
Opal
var. Opal-AN
4.DA.10SiO2 · nH2O
4.DA.10SiO2 · nH2O
Group 5 - Nitrates and Carbonates
Calcite5.AB.05CaCO3
Group 9 - Silicates
Chrysotile9.00.Mg3(Si2O5)(OH)4
Almandine9.AD.25Fe2+3Al2(SiO4)3
Sillimanite9.AF.05Al2(SiO4)O
Kyanite9.AF.15Al2(SiO4)O
Staurolite9.AF.30Fe2+2Al9Si4O23(OH)
Epidote9.BG.05a(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Cordierite9.CJ.10Mg2Al4Si5O18
Actinolite9.DE.10◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Magnesio-riebeckite9.DE.25◻Na2(Mg3Fe3+2)(Si8O22)(OH)2
Sapphirine9.DH.45Mg4(Mg3Al9)O4[Si3Al9O36]
Muscovite9.EC.15KAl2(AlSi3O10)(OH)2
Phlogopite9.EC.20KMg3(AlSi3O10)(OH)2
Albite9.FA.35Na(AlSi3O8)
var. Oligoclase9.FA.35(Na,Ca)[Al(Si,Al)Si2O8]
Natrolite9.GA.05Na2Al2Si3O10 · 2H2O
Analcime9.GB.05Na(AlSi2O6) · H2O
Unclassified
'Amphibole Supergroup'-AB2C5(T8O22)W2
'Biotite'-K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
'Chlorite Group'-
'Limonite'-
'Stilbite Subgroup'-M6-7[Al8-9Si27-28O72] · nH2O
'Tourmaline'-AD3G6(T6O18)(BO3)3X3Z
'Chrysolite'-
'Pyroxene Group'-ADSi2O6
'Garnet Group'-X3Z2(SiO4)3
'Orthopyroxene Subgroup'-
'Apatite'-Ca5(PO4)3A
'Högbomite Group'-

List of minerals for each chemical element

HHydrogen
H Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
H AnalcimeNa(AlSi2O6) · H2O
H BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
H ChrysotileMg3(Si2O5)(OH)4
H Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
H Opal var. Opal-ANSiO2 · nH2O
H Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
H MuscoviteKAl2(AlSi3O10)(OH)2
H NatroliteNa2Al2Si3O10 · 2H2O
H OpalSiO2 · nH2O
H PhlogopiteKMg3(AlSi3O10)(OH)2
H StauroliteFe22+Al9Si4O23(OH)
H Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
H Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
BBoron
B TourmalineAD3G6(T6O18)(BO3)3X3Z
CCarbon
C CalciteCaCO3
OOxygen
O Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
O AlbiteNa(AlSi3O8)
O Amphibole SupergroupAB2C5(T8O22)W2
O AnalcimeNa(AlSi2O6) · H2O
O AlmandineFe32+Al2(SiO4)3
O BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
O CalciteCaCO3
O ChrysotileMg3(Si2O5)(OH)4
O CordieriteMg2Al4Si5O18
O CorundumAl2O3
O Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
O HercyniteFe2+Al2O4
O Opal var. Opal-ANSiO2 · nH2O
O KyaniteAl2(SiO4)O
O Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
O MagnetiteFe2+Fe23+O4
O MuscoviteKAl2(AlSi3O10)(OH)2
O NatroliteNa2Al2Si3O10 · 2H2O
O Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
O OpalSiO2 · nH2O
O PhlogopiteKMg3(AlSi3O10)(OH)2
O QuartzSiO2
O SapphirineMg4(Mg3Al9)O4[Si3Al9O36]
O SillimaniteAl2(SiO4)O
O SpinelMgAl2O4
O StauroliteFe22+Al9Si4O23(OH)
O Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
O Magnetite var. Titanium-bearing MagnetiteFe2+(Fe3+,Ti)2O4
O TourmalineAD3G6(T6O18)(BO3)3X3Z
O Spinel var. CeyloniteMgAl2O4
O Pyroxene GroupADSi2O6
O Garnet GroupX3Z2(SiO4)3
O Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
O ApatiteCa5(PO4)3A
FFluorine
F BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
NaSodium
Na AlbiteNa(AlSi3O8)
Na AnalcimeNa(AlSi2O6) · H2O
Na Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
Na NatroliteNa2Al2Si3O10 · 2H2O
Na Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
MgMagnesium
Mg Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Mg BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Mg ChrysotileMg3(Si2O5)(OH)4
Mg CordieriteMg2Al4Si5O18
Mg Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
Mg PhlogopiteKMg3(AlSi3O10)(OH)2
Mg SapphirineMg4(Mg3Al9)O4[Si3Al9O36]
Mg SpinelMgAl2O4
Mg Spinel var. CeyloniteMgAl2O4
Mg Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
AlAluminium
Al AlbiteNa(AlSi3O8)
Al AnalcimeNa(AlSi2O6) · H2O
Al AlmandineFe32+Al2(SiO4)3
Al BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Al CordieriteMg2Al4Si5O18
Al CorundumAl2O3
Al Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Al HercyniteFe2+Al2O4
Al KyaniteAl2(SiO4)O
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al NatroliteNa2Al2Si3O10 · 2H2O
Al Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Al PhlogopiteKMg3(AlSi3O10)(OH)2
Al SapphirineMg4(Mg3Al9)O4[Si3Al9O36]
Al SillimaniteAl2(SiO4)O
Al SpinelMgAl2O4
Al StauroliteFe22+Al9Si4O23(OH)
Al Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
Al Spinel var. CeyloniteMgAl2O4
Al Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
SiSilicon
Si Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Si AlbiteNa(AlSi3O8)
Si AnalcimeNa(AlSi2O6) · H2O
Si AlmandineFe32+Al2(SiO4)3
Si BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Si ChrysotileMg3(Si2O5)(OH)4
Si CordieriteMg2Al4Si5O18
Si Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Si Opal var. Opal-ANSiO2 · nH2O
Si KyaniteAl2(SiO4)O
Si Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si NatroliteNa2Al2Si3O10 · 2H2O
Si Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Si OpalSiO2 · nH2O
Si PhlogopiteKMg3(AlSi3O10)(OH)2
Si QuartzSiO2
Si SapphirineMg4(Mg3Al9)O4[Si3Al9O36]
Si SillimaniteAl2(SiO4)O
Si StauroliteFe22+Al9Si4O23(OH)
Si Stilbite SubgroupM6-7[Al8-9Si27-28O72] · nH2O
Si Pyroxene GroupADSi2O6
Si Garnet GroupX3Z2(SiO4)3
PPhosphorus
P ApatiteCa5(PO4)3A
SSulfur
S ChalcopyriteCuFeS2
S MolybdeniteMoS2
S PyriteFeS2
S PyrrhotiteFe1-xS
KPotassium
K BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
K MuscoviteKAl2(AlSi3O10)(OH)2
K PhlogopiteKMg3(AlSi3O10)(OH)2
CaCalcium
Ca Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Ca CalciteCaCO3
Ca Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Ca Albite var. Oligoclase(Na,Ca)[Al(Si,Al)Si2O8]
Ca ApatiteCa5(PO4)3A
TiTitanium
Ti BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Ti Magnetite var. Titanium-bearing MagnetiteFe2+(Fe3+,Ti)2O4
Ti Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
FeIron
Fe Actinolite◻Ca2(Mg4.5-2.5Fe0.5-2.5)Si8O22(OH)2
Fe AlmandineFe32+Al2(SiO4)3
Fe BiotiteK(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Fe ChalcopyriteCuFeS2
Fe Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Fe HercyniteFe2+Al2O4
Fe Magnesio-riebeckite◻Na2(Mg3Fe23+)(Si8O22)(OH)2
Fe MagnetiteFe2+Fe23+O4
Fe PyriteFeS2
Fe PyrrhotiteFe1-xS
Fe StauroliteFe22+Al9Si4O23(OH)
Fe Magnetite var. Titanium-bearing MagnetiteFe2+(Fe3+,Ti)2O4
Fe Magnesiohögbomite-6N6S[(Mg,Fe2+)3(Al,Ti,Fe3+)8O15(OH)]6
CuCopper
Cu ChalcopyriteCuFeS2
MoMolybdenum
Mo MolybdeniteMoS2

Fossils

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Localities in this Region

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