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Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA i
Regional Level Types
Jacob's Geode Mine Mine
Hamilton City
Hancock County County
Illinois State
USA Country

Regional Level Types
Jacob's Geode Mine	Mine
Hamilton	City
Hancock County	County
Illinois	State
USA	Country

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Veiw of collection area

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Geode producing strata

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

View of the mine

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Veiw of collection area

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Geode producing strata

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

View of the mine

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Veiw of collection area

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Geode producing strata

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Latitude & Longitude (WGS84):

40° 22' 42'' North , 91° 21' 17'' West

Latitude & Longitude (decimal):

Type:

Köppen climate type:

Dfa : Hot-summer humid continental climate

Nearest Settlements:

Place	Population	Distance
Hamilton	2,853 (2017)	2.4km
Keokuk	10,609 (2017)	3.3km
Warsaw	1,551 (2017)	7.1km
Alexandria	153 (2017)	8.8km
Elvaston	161 (2017)	9.1km

Mindat Locality ID:

188554

Long-form identifier:

mindat:1:2:188554:8

GUID (UUID V4):

Geode mine operated by Gary Jacobs.

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.

ⓘ Mineral specimens

Mineral List

19 valid minerals.

Detailed Mineral List:

ⓘ Ankerite

Formula: Ca(Fe²⁺,Mg)(CO₃)₂

References:

E Harrington collection

ⓘ Baryte

Formula: BaSO₄

References:

E Harrington collection

Mahaffey, Nova, Finkelman, Robert B. (2022) The Extraordinary Variety and Complexity of Minerals in a Single Keokuk Geode from the Lower Warsaw Formation, Hamilton, Illinois, USA. Minerals, 12 (7) 914 doi:10.3390/min12070914

ⓘ Calcite

Formula: CaCO₃

References:

E Harrington collection

ⓘ Celestine

Formula: SrSO₄

References:

ⓘ Dolomite

Formula: CaMg(CO₃)₂

References:

ⓘ 'Feldspar Group'

References:

ⓘ Goethite

Formula: Fe³⁺O(OH)

References:

ⓘ Gypsum

Formula: CaSO₄ · 2H₂O

References:

E Harrington collection

ⓘ Gypsum var. Selenite

Formula: CaSO₄ · 2H₂O

References:

E Harrington collection

ⓘ Halite

Formula: NaCl

References:

ⓘ Hollandite

Formula: Ba(Mn⁴⁺₆Mn³⁺₂)O₁₆

References:

ⓘ Kaolinite

Formula: Al₂(Si₂O₅)(OH)₄

References:

E Harrington collection

ⓘ 'Limonite'

References:

https://www.mindat.org/photo-1352113.htmlIdentified by Noah Horwitz: Visual Identification

ⓘ Marcasite

Formula: FeS₂

References:

E Harrington collection

ⓘ 'Petroleum'

References:

ⓘ 'Petroleum var. Bitumen'

References:

ⓘ Pyrite

Formula: FeS₂

References:

E Harrington collection

ⓘ Quartz

Formula: SiO₂

References:

E Harrington collection

ⓘ Quartz var. Chalcedony

Formula: SiO₂

References:

ⓘ Rhodochrosite

Formula: MnCO₃

References:

ⓘ Rhodochrosite var. Ponite

Formula: (Mn,Fe)CO₃

References:

ⓘ Rutile ?

Formula: TiO₂

References:

ⓘ Siderite

Formula: FeCO₃

References:

ⓘ Sphalerite

Formula: ZnS

References:

E Harrington collection

ⓘ Sylvite

Formula: KCl

References:

ⓘ 'Xenotime' ?

References:

ⓘ Zircon ?

Formula: Zr(SiO₄)

References:

Gallery:

FeS₂ⓘ Pyrite

Pyrite

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Pyrite

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Pyrite

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

SiO₂ⓘ Quartz

Quartz

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Quartz

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

Quartz

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘ	Sphalerite	2.CB.05a	ZnS
ⓘ	Pyrite	2.EB.05a	FeS₂
ⓘ	Marcasite	2.EB.10a	FeS₂
Group 3 - Halides
ⓘ	Halite	3.AA.20	NaCl
ⓘ	Sylvite	3.AA.20	KCl
Group 4 - Oxides and Hydroxides
ⓘ	Goethite	4.00.	Fe³⁺O(OH)
ⓘ	Quartz var. Chalcedony	4.DA.05	SiO₂
ⓘ		4.DA.05	SiO₂
ⓘ	Rutile ?	4.DB.05	TiO₂
ⓘ	Hollandite	4.DK.05a	Ba(Mn⁴⁺₆Mn³⁺₂)O₁₆
Group 5 - Nitrates and Carbonates
ⓘ	Calcite	5.AB.05	CaCO₃
ⓘ	Rhodochrosite	5.AB.05	MnCO₃
ⓘ	Siderite	5.AB.05	FeCO₃
ⓘ	Rhodochrosite var. Ponite	5.AB.05	(Mn,Fe)CO₃
ⓘ	Ankerite	5.AB.10	Ca(Fe²⁺,Mg)(CO₃)₂
ⓘ	Dolomite	5.AB.10	CaMg(CO₃)₂
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘ	Baryte	7.AD.35	BaSO₄
ⓘ	Celestine	7.AD.35	SrSO₄
ⓘ	Gypsum	7.CD.40	CaSO₄ · 2H₂O
ⓘ	var. Selenite	7.CD.40	CaSO₄ · 2H₂O
Group 9 - Silicates
ⓘ	Zircon ?	9.AD.30	Zr(SiO₄)
ⓘ	Kaolinite	9.ED.05	Al₂(Si₂O₅)(OH)₄
Unclassified
ⓘ	'Feldspar Group'	-
ⓘ	'Limonite'	-
ⓘ	'Xenotime' ?	-
ⓘ	'Petroleum var. Bitumen'	-
ⓘ	''	-

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Goethite	Fe³⁺O(OH)
H	ⓘ Gypsum	CaSO₄ · 2H₂O
H	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
H	ⓘ Gypsum var. Selenite	CaSO₄ · 2H₂O
C	Carbon
C	ⓘ Ankerite	Ca(Fe²⁺,Mg)(CO₃)₂
C	ⓘ Calcite	CaCO₃
C	ⓘ Dolomite	CaMg(CO₃)₂
C	ⓘ Rhodochrosite	MnCO₃
C	ⓘ Siderite	FeCO₃
C	ⓘ Rhodochrosite var. Ponite	(Mn,Fe)CO₃
O	Oxygen
O	ⓘ Ankerite	Ca(Fe²⁺,Mg)(CO₃)₂
O	ⓘ Baryte	BaSO₄
O	ⓘ Calcite	CaCO₃
O	ⓘ Celestine	SrSO₄
O	ⓘ Quartz var. Chalcedony	SiO₂
O	ⓘ Dolomite	CaMg(CO₃)₂
O	ⓘ Goethite	Fe³⁺O(OH)
O	ⓘ Gypsum	CaSO₄ · 2H₂O
O	ⓘ Hollandite	Ba(Mn₆⁴⁺Mn₂³⁺)O₁₆
O	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
O	ⓘ Quartz	SiO₂
O	ⓘ Rhodochrosite	MnCO₃
O	ⓘ Rutile	TiO₂
O	ⓘ Siderite	FeCO₃
O	ⓘ Zircon	Zr(SiO₄)
O	ⓘ Gypsum var. Selenite	CaSO₄ · 2H₂O
O	ⓘ Rhodochrosite var. Ponite	(Mn,Fe)CO₃
Na	Sodium
Na	ⓘ Halite	NaCl
Mg	Magnesium
Mg	ⓘ Ankerite	Ca(Fe²⁺,Mg)(CO₃)₂
Mg	ⓘ Dolomite	CaMg(CO₃)₂
Al	Aluminium
Al	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
Si	Silicon
Si	ⓘ Quartz var. Chalcedony	SiO₂
Si	ⓘ Kaolinite	Al₂(Si₂O₅)(OH)₄
Si	ⓘ Quartz	SiO₂
Si	ⓘ Zircon	Zr(SiO₄)
S	Sulfur
S	ⓘ Baryte	BaSO₄
S	ⓘ Celestine	SrSO₄
S	ⓘ Gypsum	CaSO₄ · 2H₂O
S	ⓘ Marcasite	FeS₂
S	ⓘ Pyrite	FeS₂
S	ⓘ Sphalerite	ZnS
S	ⓘ Gypsum var. Selenite	CaSO₄ · 2H₂O
Cl	Chlorine
Cl	ⓘ Halite	NaCl
Cl	ⓘ Sylvite	KCl
K	Potassium
K	ⓘ Sylvite	KCl
Ca	Calcium
Ca	ⓘ Ankerite	Ca(Fe²⁺,Mg)(CO₃)₂
Ca	ⓘ Calcite	CaCO₃
Ca	ⓘ Dolomite	CaMg(CO₃)₂
Ca	ⓘ Gypsum	CaSO₄ · 2H₂O
Ca	ⓘ Gypsum var. Selenite	CaSO₄ · 2H₂O
Ti	Titanium
Ti	ⓘ Rutile	TiO₂
Mn	Manganese
Mn	ⓘ Hollandite	Ba(Mn₆⁴⁺Mn₂³⁺)O₁₆
Mn	ⓘ Rhodochrosite	MnCO₃
Mn	ⓘ Rhodochrosite var. Ponite	(Mn,Fe)CO₃
Fe	Iron
Fe	ⓘ Ankerite	Ca(Fe²⁺,Mg)(CO₃)₂
Fe	ⓘ Goethite	Fe³⁺O(OH)
Fe	ⓘ Marcasite	FeS₂
Fe	ⓘ Pyrite	FeS₂
Fe	ⓘ Siderite	FeCO₃
Fe	ⓘ Rhodochrosite var. Ponite	(Mn,Fe)CO₃
Zn	Zinc
Zn	ⓘ Sphalerite	ZnS
Sr	Strontium
Sr	ⓘ Celestine	SrSO₄
Zr	Zirconium
Zr	ⓘ Zircon	Zr(SiO₄)
Ba	Barium
Ba	ⓘ Baryte	BaSO₄
Ba	ⓘ Hollandite	Ba(Mn₆⁴⁺Mn₂³⁺)O₁₆

Mindat Articles

Micro-mineralogy of a single Keokuk geode; how complex can it get? by Kevin Conroy

Other Regions, Features and Areas containing this locality

North AmericaContinent

North America PlateTectonic Plate

Illinois BasinBasin
Mazatzal DomainDomain
Mazatzal TerraneVolcanic Arc

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References

https://rockhound.in/places/united-states/illinois/hamilton/dig-sites/jacobs-geode-shop-mine/

https://jacobs-mine.edan.io/

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Select Mineral List Type

Commodity List

Mineral List

Detailed Mineral List:

Gallery:

List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Mindat Articles

Other Regions, Features and Areas containing this locality

References

Jacob's Geode Mine, Hamilton, Hancock County, Illinois, USA i
Regional Level Types
Jacob's Geode Mine Mine
Hamilton City
Hancock County County
Illinois State
USA Country