Description: small crystals and masses in the limestone caprock, also as yellow coatings where black hydrocarbon-rich shales are exposed in small gullies.

References:

Smith, Arthur E. (1980) Mineralogical Notes - Pyrrhotite Nodules from Texas Gulf Coast Salt Domes. The Mineralogical Record, 11 (2) 100-101

Smith, Arthur E. (1991) Texas Mineral Locality Index. Rocks & Minerals, 66 (3) 196-224 doi:10.1080/00357529.1991.11761622

ⓘ Pyrite

Formula: FeS₂

Locality: Damon Mound Salt Dome, Damon, Brazoria County, Texas, USA

Habit: octahedra; botryoidal coatings

References:

Smith, Arthur E. (1980) Mineralogical Notes - Pyrrhotite Nodules from Texas Gulf Coast Salt Domes. The Mineralogical Record, 11 (2) 100-101

Smith, Arthur E. (1991) Texas Mineral Locality Index. Rocks & Minerals, 66 (3) 196-224 doi:10.1080/00357529.1991.11761622

ⓘ Pyrrhotite

Formula: Fe_1-xS

Locality: Damon Mound Salt Dome, Damon, Brazoria County, Texas, USA

Description: Smith (1980): "The pyrrhotite nodules vary in size from 1 mm to slightly over 4 cm in diameter. The outer surface consists of platy hexagonal crystals arranged with pinacoid faces subparallel. The crystals range from less than 0.5 mm to over 5 cm in diameter and vary in color from metallic gray to bronze, but rapidly weather to a very rusty brown on exposure. Most of the nodules react weakly to a magnet. Some do not and may actually be pseudomorphs. Rarely, isolated small groups and single microcrystals occur on thin plates of massive pyrrhotite. The interior of the nodules has a somewhat foliated structure that radiates from the center. The centers of many nodules are hollow but others are filled with intergrown, clear, tabular barite crystals. Microcrystals of barite also occur in cracks. Both occurrences of barite are of secondary origin. Tiny crystals of pyrite may occur on the pyrrhotite crystals. The smaller nodules (0.5 to 1 cm in diameter) are actually flattened rosettes that occur alone or in flat aggregates. Some of the rosettes have a crude but distinct hexagonal outline. The larger nodules (1 to 4 cm in diameter) always occur alone and are rounded. These nodules may also have a crude hexagonal outline, a circular outline, or a star-shaped outline."

References:

Smith, Arthur E. (1980) Mineralogical Notes - Pyrrhotite Nodules from Texas Gulf Coast Salt Domes. The Mineralogical Record, 11 (2) 100-101

Smith, Arthur E. (1991) Texas Mineral Locality Index. Rocks & Minerals, 66 (3) 196-224 doi:10.1080/00357529.1991.11761622

ⓘ Siderite

Formula: FeCO₃

Locality: Damon Mound Salt Dome, Damon, Brazoria County, Texas, USA

References:

Smith, Arthur E. (1991) Texas Mineral Locality Index. Rocks & Minerals, 66 (3) 196-224 doi:10.1080/00357529.1991.11761622

ⓘ Sphalerite

Formula: ZnS

Locality: Damon Mound Salt Dome, Damon, Brazoria County, Texas, USA

Fluorescence: Deep red

References:

Smith, Arthur E. (1991) Texas Mineral Locality Index. Rocks & Minerals, 66 (3) 196-224 doi:10.1080/00357529.1991.11761622

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘ	Native Sulphur	1.CC.05	S₈
Group 2 - Sulphides and Sulfosalts
ⓘ	Sphalerite	2.CB.05a	ZnS
ⓘ	Pyrrhotite	2.CC.10	Fe_1-xS
ⓘ	Pyrite	2.EB.05a	FeS₂
ⓘ	Marcasite	2.EB.10a	FeS₂
Group 3 - Halides
ⓘ	Halite	3.AA.20	NaCl
Group 5 - Nitrates and Carbonates
ⓘ	Calcite	5.AB.05	CaCO₃
ⓘ	Siderite	5.AB.05	FeCO₃
ⓘ	Dolomite	5.AB.10	CaMg(CO₃)₂
ⓘ	Aragonite	5.AB.15	CaCO₃
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘ	Anhydrite	7.AD.30	CaSO₄
ⓘ	Baryte	7.AD.35	BaSO₄
ⓘ	Melanterite	7.CB.35	Fe²⁺(H₂O)₆SO₄ · H₂O
ⓘ	Gypsum	7.CD.40	CaSO₄ · 2H₂O

List of minerals for each chemical element

H	Hydrogen
H	ⓘ Gypsum	CaSO₄ · 2H₂O
H	ⓘ Melanterite	Fe²⁺(H₂O)₆SO₄ · H₂O
C	Carbon
C	ⓘ Aragonite	CaCO₃
C	ⓘ Calcite	CaCO₃
C	ⓘ Dolomite	CaMg(CO₃)₂
C	ⓘ Siderite	FeCO₃
O	Oxygen
O	ⓘ Anhydrite	CaSO₄
O	ⓘ Aragonite	CaCO₃
O	ⓘ Baryte	BaSO₄
O	ⓘ Calcite	CaCO₃
O	ⓘ Dolomite	CaMg(CO₃)₂
O	ⓘ Gypsum	CaSO₄ · 2H₂O
O	ⓘ Melanterite	Fe²⁺(H₂O)₆SO₄ · H₂O
O	ⓘ Siderite	FeCO₃
Na	Sodium
Na	ⓘ Halite	NaCl
Mg	Magnesium
Mg	ⓘ Dolomite	CaMg(CO₃)₂
S	Sulfur
S	ⓘ Anhydrite	CaSO₄
S	ⓘ Baryte	BaSO₄
S	ⓘ Gypsum	CaSO₄ · 2H₂O
S	ⓘ Marcasite	FeS₂
S	ⓘ Melanterite	Fe²⁺(H₂O)₆SO₄ · H₂O
S	ⓘ Pyrite	FeS₂
S	ⓘ Pyrrhotite	Fe_1-xS
S	ⓘ Sphalerite	ZnS
S	ⓘ Native Sulphur	S₈
Cl	Chlorine
Cl	ⓘ Halite	NaCl
Ca	Calcium
Ca	ⓘ Anhydrite	CaSO₄
Ca	ⓘ Aragonite	CaCO₃
Ca	ⓘ Calcite	CaCO₃
Ca	ⓘ Dolomite	CaMg(CO₃)₂
Ca	ⓘ Gypsum	CaSO₄ · 2H₂O
Fe	Iron
Fe	ⓘ Marcasite	FeS₂
Fe	ⓘ Melanterite	Fe²⁺(H₂O)₆SO₄ · H₂O
Fe	ⓘ Pyrite	FeS₂
Fe	ⓘ Pyrrhotite	Fe_1-xS
Fe	ⓘ Siderite	FeCO₃
Zn	Zinc
Zn	ⓘ Sphalerite	ZnS
Ba	Barium
Ba	ⓘ Baryte	BaSO₄

Localities in this Region

USA

Texas
- Brazoria County
  - Damon
    - Damon Mound Salt Dome
    - Dresser Minerals

Other Regions, Features and Areas containing this locality

North AmericaContinent

North America PlateTectonic Plate

Gulf of Mexico BasinBasin
Northern Gulf of Mexico MarginPassive Margin
Sabine DomainDomain

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Damon, Brazoria County, Texas, USAiRegional Level TypesDamonVillage Brazoria CountyCounty TexasState USACountry function showexplain() { $("#locexplain").toggle(); if (typeof movemap === "function") movemap(); }

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List of minerals arranged by Strunz 10th Edition classification

List of minerals for each chemical element

Localities in this Region

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Damon, Brazoria County, Texas, USA i
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