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Roxbury Iron Mine (Shepaug Iron Company Mine; Shepaug Spathic Iron and Steel Company Mine), Mine Hill (Ore Hill), Roxbury, Litchfield Co., Connecticut, USAi
Regional Level Types
Roxbury Iron Mine (Shepaug Iron Company Mine; Shepaug Spathic Iron and Steel Company Mine)Mine
Mine Hill (Ore Hill)Hill
Roxbury- not defined -
Litchfield Co.County
ConnecticutState
USACountry

This page kindly sponsored by Donald B Peck
Key
Latitude & Longitude (WGS84):
41° 34' 6'' North , 73° 20' 24'' West
Latitude & Longitude (decimal):
Locality type:
Nearest Settlements:
PlacePopulationDistance
New Milford6,523 (2017)5.8km
Washington3,466 (2017)7.4km
Woodbury9,755 (2017)11.2km
Woodbury Center1,294 (2017)11.6km
New Preston1,182 (2017)11.9km


A series of at least 7 veins, primarily siderite and quartz, formed along minor faults trending about 120 degrees E and dipping SW at 75 to 90 degrees. The largest vein is 2 to 3 meters thick, at least 600 meters long and extends at least 60 meters down, probably much more. It is one of the largest deposits of siderite in North America. Drifts were cut on 3 of the veins, with 3 levels with separate adits and numerous shafts put in on the largest vein. Three of the 5 pure quartz veins in the area were also mined. Maps and plans of the veins and mines are shown by Bell and Mayerfeld (1982). Januzzi (1976) includes sketches and photographs from inside the mine. Besides siderite the locality is best known for its excellent pyrite crystals.

The first confirmed mining at this site was in 1750, about that time, Moses Hurlbut and Abel Hawley are said to have worked Mine Hill for silver and lead. About 1760 a company headed by two brothers named Brownson worked the mine energetically under the supervision of a German goldsmith named Feuchter; two shafts were sunk, one going down 175 feet from the top of the hill, into the vein of ore. This search for silver in the relatively sparse galena continued for several years until the available funds were exhausted.

A new company was organized; the vein traced down the surface of the hill toward the river and horizontal drifts were made. Several other companies followed, working the mine for silver and lead, but there was not enough galena and these late 18th century operations were short lived. The last operation recognized the iron potential of the ore, but did not pursue it.

By about 1816 Prof. Benjamin Silliman of Yale identified iron in the form of siderite as a valuable ore, this was followed by inspections in 1830 by Prof. Charles Shepard. At last the vein’s value as an iron-ore was appreciated, and by 1830 David Stiles began operating to extract it. His operations became tied up by lawsuits from previous operators or leaseholders.

Finally, in 1865, the Shepaug Spathic Iron and Steel Company was formed after exploring the prospect, running some of the ore through other furnaces, and seeking the best advice available from an economic geologist, mining engineers and metallurgists, plus four Yale professors: Brush, Porter, Dana and Silliman (senior, now 85 years old). Professor George Brush wrote on May 30, 1864: “The ore...is spathic, or sparry iron ore....something over 40% metallic iron, most highly prized of iron ores, comparatively rare...It produces a white pig iron…well adapted for conversion to steel.” Quality steel was being made in Prussia and Styria from siderite, so the thinking was that the presence of carbon in the iron ore would simplify the 3-step steel making process and allow a more direct, larger scale, and thus cheaper process.

In 1867, the company name changed to The American Silver Steel Company. It greatly expanded the mining and built the railbed, furnaces and facilities whose ruins are now preserved at the site. The steel works were not successful apparently because "Silliman had incorrectly assessed the ore's steelmaking potential, and that none of the experts it had hired could run the steelworks" (Gordon and Raber, 2000). They could not replicate the "feel" the Europeans had for their process (which lacked any method of directly measuring the carbon content) and the presence of carbon in the ore was of no consequence to the steel making process as it worked the same way with the roasted iron oxide ore (Bell and Mayerfeld, 1982).

After some problems with the blast furnace in 1868, the mining and smelting ran well, producing pig iron until 1872, when a change over to a hot blast ruined the furnace and all activity ended. Because the original plan was to produce quality, high-priced steel from the pig iron, this furnace was not competitive as solely a pig iron producer. The costly underground hard rock mining and the cost of roasting the ore to remove the sulfides and carbonate content were not incurred by the open pit, "soft ore" goethite mining operations elsewhere in the Connecticut/Massachusetts/New York iron mining district.

Sometime in the early 1900s the Columbia School of Mines arranged to use the mine for field study by students of mining engineering. They reinforced the middle drift adit with concrete. In the summer, the cool, moist air exiting this adit sends a breath of refreshing fog across the trail.

The mine is now part of the Roxbury Land Trust’s Mine Hill Preserve. The complex is listed on the National Register of Historic Places. The adits and shafts have been gated off to prevent human entrance but allow access by the bats that now make it their home.

Regions containing this locality

North America PlateTectonic Plate

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

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


Mineral List


22 valid minerals.

Detailed Mineral List:

Anglesite ?
Formula: PbSO4
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Aragonite
Formula: CaCO3
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Arsenopyrite
Formula: FeAsS
Habit: rectangular prisms
Colour: gray
Description: Usually as aggregates of < 1cm crystals embedded in yellowish matrix.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409; Schairer (1931)
Calcite
Formula: CaCO3
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409
Cerussite
Formula: PbCO3
Habit: micro-crystalline crusts
Colour: pale gray to white
Fluorescence: greenish-white
Description: Micro-crusts on siderite from alteration of galena, fluoresces in both SW and LW, unlike hydrozincite.
Reference: Harold Moritz collection
Chalcopyrite
Formula: CuFeS2
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409; Schairer (1931)
Clinochlore ?
Formula: Mg5Al(AlSi3O10)(OH)8
Habit: encrustation
Colour: dull gray-green
Description: As a very fine-grained crust a few mm thick on siderite rhombs.
Reference: Januzzi (1976)
Copiapite
Formula: Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
Reference: Schairer, J. F. (1931), The Minerals of Connecticut. State Geological and Natural History Survey, Hartford Connecticut Bulletin 51 Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Galena
Formula: PbS
Habit: massive, cubic
Colour: gray
Description: Generally as cleavable masses up to 25 pounds embedded in siderite and/or quartz. Crystals up to 1" in pockets.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409; Schooner (1961)
Goethite
Formula: α-Fe3+O(OH)
Habit: massive, botryoidal
Colour: brown to red-brown
Description: Much of the darker colored siderite is actually goethite pseudomorphs after siderite. Rarely bortyoidal. Stalactitic formations also formed on the walls and ceilings inside the mine.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Greenockite ?
Formula: CdS
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Hematite
Formula: Fe2O3
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Hydrozincite
Formula: Zn5(CO3)2(OH)6
Habit: coatings
Colour: grayish-white
Fluorescence: blue-white
Description: Typically as gray-white crusts and coatings associated with sphalerite.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409
Langite ?
Formula: Cu4(SO4)(OH)6 · 2H2O
Habit: earthy crusts
Colour: blue-green
Description: Scant blue-green crusts on siderite from the ore vein, labeled as langite but with no supporting data and no crystals available to differentiate it from other secondary copper minerals, which are rather rare at this locality to begin with.
Reference: Former Ronald Januzzi collection
'Limonite'
Formula: (Fe,O,OH,H2O)
Habit: massive
Colour: brown
Description: Pseudomorphous after pyrite and siderite
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Löllingite
Formula: FeAs2
Description: Found "sparingly". Associated with siderite and sulfides.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Schairer (1931)
Malachite
Formula: Cu2(CO3)(OH)2
Colour: green
Description: As coatings.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Januzzi (1994)
Melanterite
Formula: Fe2+(H2O)6SO4 · H2O
Description: Alteration of pyrite.
Reference: Schairer, J. F. (1931), The Minerals of Connecticut. State Geological and Natural History Survey, Hartford Connecticut Bulletin 51 Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Opal
Formula: SiO2 · nH2O
Habit: coatings, crusts
Colour: colorless
Fluorescence: green
Description: Typically as colorless crusts or coatings that escape notice except when illuminated by SW UV, which causes a bright green fluorescence.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Opal var: Opal-AN
Formula: SiO2 · nH2O
Habit: coatings, crusts
Colour: colorless
Fluorescence: green
Description: Typically as colorless crusts or coatings that escape notice except when illuminated by SW UV, which causes a bright green fluorescence.
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State
Pyrite
Formula: FeS2
Habit: pyritohedral and in combination with cube
Colour: pale brassy
Description: Excellent striated to smooth-faced pyritohedrons up to several cm across, commonly in aggregates, embedded in siderite and sphalerite
Reference: Rocks & Minerals (1995) 70:396-409; Schooner (1961)
Quartz
Formula: SiO2
Habit: elongated prisms with rhombohedral terminations
Colour: clear to white
Description: Radiating, elongated crystals typically formed early and then were surrounded by siderite and sulfide minerals. Some free, thicker crystals are also known. As a druse epimorphic over a now dissolved cubic mineral (fluorite?, galena?) up to about 1 cm.
Reference: Rocks & Minerals (1995) 70:396-409; Ronald Januzzi collection
Siderite
Formula: FeCO3
Habit: rhombohedrons
Colour: tan to light brown
Description: Typically as cleavable masses, some lustrous, curved rhombohedral crystals are found in small cavities or frozen in quartz
Reference: Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 169.; Rocks & Minerals (1995) 70:396-409
Sphalerite
Formula: ZnS
Habit: cleavable masses, tetrahedral
Colour: black, pale to dark brown
Description: Typically as cleavable masses embedded in siderite, euhedral crystals rare and usually small, but "some beautiful big crystals are known" (Schooner 1961).
Reference: Januzzi, 1976. Mineral Localities of CT and Southeastern NY State; Rocks & Minerals (1995) 70:396-409; Schooner (1961)

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Arsenopyrite2.EB.20FeAsS
Chalcopyrite2.CB.10aCuFeS2
Galena2.CD.10PbS
Greenockite ?2.CB.45CdS
Löllingite2.EB.15aFeAs2
Pyrite2.EB.05aFeS2
Sphalerite2.CB.05aZnS
Group 4 - Oxides and Hydroxides
Goethite4.00.α-Fe3+O(OH)
Hematite4.CB.05Fe2O3
Opal4.DA.10SiO2 · nH2O
var: Opal-AN4.DA.10SiO2 · nH2O
Quartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
Aragonite5.AB.15CaCO3
Calcite5.AB.05CaCO3
Cerussite5.AB.15PbCO3
Hydrozincite5.BA.15Zn5(CO3)2(OH)6
Malachite5.BA.10Cu2(CO3)(OH)2
Siderite5.AB.05FeCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
Anglesite ?7.AD.35PbSO4
Copiapite7.DB.35Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
Langite ?7.DD.10Cu4(SO4)(OH)6 · 2H2O
Melanterite7.CB.35Fe2+(H2O)6SO4 · H2O
Group 9 - Silicates
Clinochlore ?9.EC.55Mg5Al(AlSi3O10)(OH)8
Unclassified Minerals, Rocks, etc.
'Limonite'-(Fe,O,OH,H2O)

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmXp, with m:p = 1:1
Galena2.8.1.1PbS
Greenockite ?2.8.7.2CdS
Sphalerite2.8.2.1ZnS
AmBnXp, with (m+n):p = 1:1
Chalcopyrite2.9.1.1CuFeS2
AmBnXp, with (m+n):p = 1:2
Arsenopyrite2.12.4.1FeAsS
Löllingite2.12.2.9FeAs2
Pyrite2.12.1.1FeS2
Group 4 - SIMPLE OXIDES
A2X3
Hematite4.3.1.2Fe2O3
Group 6 - HYDROXIDES AND OXIDES CONTAINING HYDROXYL
XO(OH)
Goethite6.1.1.2α-Fe3+O(OH)
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
Cerussite14.1.3.4PbCO3
Siderite14.1.1.3FeCO3
Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
Malachite16a.3.1.1Cu2(CO3)(OH)2
Hydrozincite16a.4.1.1Zn5(CO3)2(OH)6
Group 28 - ANHYDROUS ACID AND NORMAL SULFATES
AXO4
Anglesite ?28.3.1.3PbSO4
Group 29 - HYDRATED ACID AND NORMAL SULFATES
AXO4·xH2O
Melanterite29.6.10.1Fe2+(H2O)6SO4 · H2O
Group 31 - HYDRATED SULFATES CONTAINING HYDROXYL OR HALOGEN
(AB)4(XO4)Zq·xH2O
Langite ?31.4.3.1Cu4(SO4)(OH)6 · 2H2O
Miscellaneous
Copiapite31.10.5.1Fe2+Fe3+4(SO4)6(OH)2 · 20H2O
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings interlayered 1:1, 2:1, and octahedra
Clinochlore ?71.4.1.4Mg5Al(AlSi3O10)(OH)8
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Quartz75.1.3.1SiO2
Si Tetrahedral Frameworks - SiO2 with H2O and organics
Opal75.2.1.1SiO2 · nH2O
Unclassified Minerals, Mixtures, etc.
Aragonite-CaCO3
'Limonite'-(Fe,O,OH,H2O)
Opal
var: Opal-AN
-SiO2 · nH2O

List of minerals for each chemical element

HHydrogen
H CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
H MelanteriteFe2+(H2O)6SO4 · H2O
H HydrozinciteZn5(CO3)2(OH)6
H Goethiteα-Fe3+O(OH)
H Opal (var: Opal-AN)SiO2 · nH2O
H Limonite(Fe,O,OH,H2O)
H MalachiteCu2(CO3)(OH)2
H OpalSiO2 · nH2O
H ClinochloreMg5Al(AlSi3O10)(OH)8
H LangiteCu4(SO4)(OH)6 · 2H2O
CCarbon
C SideriteFeCO3
C AragoniteCaCO3
C CalciteCaCO3
C HydrozinciteZn5(CO3)2(OH)6
C CerussitePbCO3
C MalachiteCu2(CO3)(OH)2
OOxygen
O SideriteFeCO3
O QuartzSiO2
O CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
O AragoniteCaCO3
O CalciteCaCO3
O HematiteFe2O3
O MelanteriteFe2+(H2O)6SO4 · H2O
O HydrozinciteZn5(CO3)2(OH)6
O CerussitePbCO3
O Goethiteα-Fe3+O(OH)
O Opal (var: Opal-AN)SiO2 · nH2O
O Limonite(Fe,O,OH,H2O)
O MalachiteCu2(CO3)(OH)2
O OpalSiO2 · nH2O
O AnglesitePbSO4
O ClinochloreMg5Al(AlSi3O10)(OH)8
O LangiteCu4(SO4)(OH)6 · 2H2O
MgMagnesium
Mg ClinochloreMg5Al(AlSi3O10)(OH)8
AlAluminium
Al ClinochloreMg5Al(AlSi3O10)(OH)8
SiSilicon
Si QuartzSiO2
Si Opal (var: Opal-AN)SiO2 · nH2O
Si OpalSiO2 · nH2O
Si ClinochloreMg5Al(AlSi3O10)(OH)8
SSulfur
S PyriteFeS2
S ArsenopyriteFeAsS
S CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
S SphaleriteZnS
S GalenaPbS
S MelanteriteFe2+(H2O)6SO4 · H2O
S ChalcopyriteCuFeS2
S GreenockiteCdS
S AnglesitePbSO4
S LangiteCu4(SO4)(OH)6 · 2H2O
CaCalcium
Ca AragoniteCaCO3
Ca CalciteCaCO3
FeIron
Fe SideriteFeCO3
Fe PyriteFeS2
Fe ArsenopyriteFeAsS
Fe CopiapiteFe2+Fe43+(SO4)6(OH)2 · 20H2O
Fe LöllingiteFeAs2
Fe HematiteFe2O3
Fe MelanteriteFe2+(H2O)6SO4 · H2O
Fe ChalcopyriteCuFeS2
Fe Goethiteα-Fe3+O(OH)
Fe Limonite(Fe,O,OH,H2O)
CuCopper
Cu ChalcopyriteCuFeS2
Cu MalachiteCu2(CO3)(OH)2
Cu LangiteCu4(SO4)(OH)6 · 2H2O
ZnZinc
Zn SphaleriteZnS
Zn HydrozinciteZn5(CO3)2(OH)6
AsArsenic
As ArsenopyriteFeAsS
As LöllingiteFeAs2
CdCadmium
Cd GreenockiteCdS
PbLead
Pb GalenaPbS
Pb CerussitePbCO3
Pb AnglesitePbSO4

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Shepard, Charles U. (1831), Notice of the Mine of Spathic Iron (Steel ore) of New Milford, and of the Iron Works of Salisbury, in the State of Connecticut. American Journal of Science, 1st series, 19: 311-326.
Shepard, Charles U. (1837), A Report on the Geological Survey of Connecticut. Hamlen, New Haven.
Pynchon, W. H. C. (1899), Iron Mining in Connecticut. The Connecticut Magazine, 5: 20-26.
Schrader, Frank C., Stone, Ralph W., and Sanford, Samuel. (1917), Useful Minerals of the United States. U. S. Geological Survey Bulletin 624: 97-101.
Schairer, J. F. (1931), The Minerals of Connecticut. State Geological and Natural History Survey Bulletin 51.
Keith, Herbert C. (1935), The Early Iron Industry of Connecticut. Part I. History and Relics. Connecticut Society of Civil Engineers, Inc.
Harte, Charles Rufus. (1935), The Early Iron Industry of Connecticut. Part II. The Connecticut Blast Furnaces and Furnace Practice. Connecticut Society of Civil Engineers, Inc.
Elwell, Wilbur J. (1936), Mineral Collecting by Hydroplane. Rocks and Minerals: 11(6): 92-3.
Harte, Charles Rufus. (1944), Connecticut's Iron and Copper. 60th Annual Report of The Connecticut Society of Civil Engineers, Incorporated.
Perry, Clay (1946), New England's Buried Treasure (NY: Stephen Daye Press).
Januzzi, Ronald E. (1959), The Minerals of Western Connecticut and Southeastern New York State. The Mineralogical Press, Danbury, Connecticut.
Schooner, Richard. (1961), The Mineralogy of Connecticut. Fluorescent House, Branford, Connecticut.
Hull, Daniel R. (1966), Bewitched Mine Hill, The Silver-Lead-Iron Mine of Roxbury, Connecticut. The Old Woodbury Historical Society, Woodbury, Connecticut.
Ryerson, Kathleen. (1972), Rock Hound's Guide to Connecticut. Pequot Press.
Januzzi, Ronald E. (1976), Mineral Localities of Connecticut and Southeastern New York State. The Mineralogical Press, Danbury, Connecticut.
Webster, Bud. (1978), Mineral Collector’s Field Guide Connecticut. Privately published.
Bell and Mayerfeld (1982): Time and Land: The Story of Mine Hill (Roxbury Land Trust and Yale School of Forestry and Environmental Studies).
Weber, Marcelle H. and Earle C. Sullivan. (1995), Connecticut Mineral Locality Index. Rocks & Minerals (Connecticut Issue): 70(6): 399.
Kirby, Ed. (1998), Echoes of Iron in Connecticut's Northwestern Corner. Sharon Historical Society: 109.
Gordon, Robert and Michael Raber. (2000), Industrial Heritage in Northwest Connecticut, A Guide to History and Archaeology. Volume 25 of the Memoirs of the Connecticut Academy of Arts and Sciences, New Haven: 63-4.
Pawloski, John A. (2006), Connecticut Mining (Mt. Pleasant, SC: Arcadia Publishing): 50-51; 61.

External Links

Bell and Mayerfeld (1982) can be found here - http://www.roxburylandtrust.org/minehill.html


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