Stamford, Fairfield County, Connecticut, USAi

Regional Level Types
Stamford	- not defined -
Fairfield County	County
Connecticut	State
USA	Country

Description: On North Stamford Avenue, "good sized"

Reference: Brown, Samuel C. (1930): Mineral Collecting In Southwestern Connecticut. Rocks & Minerals, vol. 5, no. 1, p. 13.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro needles, acicular

Colour: white

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro radiating clusters, aggregates, druses

Colour: deep green, sky blue

Description: Henderson (1967) reports: deep green crystals of quite variable habit up to 0.5 mm in size. The terminal planes of single crystals were generally bright, while faces in the prism zone were rounded and striated (Fig. 3). It also occurred as radiating groups and in irregular aggregates, sometimes with a single larger crystal perched on top. Druses of atacamite on vesicles were common. It was most frequently found close to or on cuprite, but occasionally appeared to be on malachite. Identification was based on its solubility in dilute hydrochloric and nitric acids, a positive test for halogen, and negative tests for carbonate and sulfate. The atacamite showed parallel extinction and weak birefringence, the two together ruling our malachite, antlerite and brochantite. The mineral was distinguished from paratacamite by its crystal form. On occasion, crystals corresponding to atacamite were found but with a sky blue color. These may well be pseudomorphs of rosasite after atacamite.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Reference: Brown, Samuel C. (1930): Mineral Collecting In Southwestern Connecticut. Rocks & Minerals, vol. 5, no. 1, p. 13.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro tabular

Colour: blue

Description: two small groups of deep blue, very tiny platy crystals associated with malachite. The crystals were flat tablets with a vitreous luster.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Description: "dead ringers for English material"

Reference: Ryerson (1972): Rock Hound's Guide to Conn.; Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro arborescent, octahedral

Description: Henderson (1967) reports: occurs both massive and in crystals. The massive material is in irregular masses up to an inch or two in length or as small beads formed on cooling of molten material. The larger masses are invariably coated with ocher copper minerals, and usually are associated with coal or coke. Crystals are found in vesicles in slag. Up to 1.0 mm in length, the crystals are highly distorted and usually arborescent. A few specimens appeared to be octahedral in habit. Many crystals are covered with cuprite crystals, and a few pseudo-morphs of cuprite after copper occur.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro cubic, octahedral, modified by dodecahedron

Colour: deep red

Description: Henderson (1967) reports: as large masses and as crystals. Crystallized material showed the cube and/or octahedron; the dodecahedron was less commonly found, and then only as modifying faces. The deep red crystals were up to 0.5 mm in length, and occurred singly or in groups, usually on massive cuprite. Besides the equant variety, cuprite was also found as acicular crystals of chalcotrichite.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: acicular

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Fluorescence: blue-white

Description: Masses, with strong blue-white fluorescence. "dead ringers for English material"

Reference: Ryerson (1972): Rock Hound's Guide to Conn.; Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Description: "dead ringers for English material"

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: needle druses

Colour: light green

Description: small, light green, velvety needles in druses

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Colour: blue

Description: At the West Avenue Quarry.

Reference: Brown, Samuel C. (1930): Mineral Collecting In Southwestern Connecticut. Rocks & Minerals, vol. 5, no. 1, p. 13.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro tetrahedra, etched to skeletal or in parallel groups

Colour: colorless to white

Description: Henderson (1967) reports: colorless translucent to white opaque 0.5 mm tetrahedra with and on cuprite and atacamite. Some of the crystals showed triangular etch pits on the tetrahedron faces (Fig. 1) and many were skeletal (Fig. 2) or occurred in parallel growth. Identification was made as follows. Very few white tetrahedral minerals are known, and of these, only nantokite CuCl and marshite CuI were likely to form from copper in the presence of sea water. Both these minerals are optically isotropic, and the above material was found to be so. In addition, the index of refraction was found to be about 1.93. Nantokite has an index of 1.930 while marshite has an index of 2.346. As a matter of fact, the index of refraction is alone sufficient to identify this mineral as nantokite since only a handful of minerals have indices as high as 1.9, and the above are the only tetrahedral minerals in the group. Many of the nantokite crystals were altered in part or entirely to a lime green mineral, and a few to a sulfur yellow material. It is interesting to note that nantokite has been reported to alter in air to the green mineral paratacamite.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Colour: lime green

Description: Many of the nantokite crystals were altered in part or entirely to a lime green mineral, which may be paratacamite.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Habit: micro duses to radiating acicular aggregates

Colour: pale blue

Description: Henderson (1967) reports: found in several habits. Druses of very small, pale blue, velvety crystals were common; on occasion, the larger crystals of acicular habit formed radiating aggregates. A few single crystals were noted: these formed tapering prisms with wedge shape terminations. An occasional arborescent group of crystals was noted (Fig. 4). The rosasite tended to be further from copper and cuprite than either the nantokite or atacamite and often occurred in the seams of half-consumed coke. The material was identified as rosasite by its color, crystal form and positive test for carbonate and negative test for sulfate. Its optical properties were those of rosasite. It was distinguished from the high-zinc end member of the series, aurichalcite, by its color, aurichalcite tend¬ing toward green.

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Habit: radiating aggregates

Description: At the West Avenue Quarry.

Reference: Brown, Samuel C. (1930): Mineral Collecting In Southwestern Connecticut. Rocks & Minerals, vol. 5, no. 1, p. 13.

Locality: Dyke Park, Stamford, Fairfield County, Connecticut, USA

Reference: Henderson, William, A., Jr. (1967), A Copper Analog of Laurium, Greece. Rocks & Minerals: 42(5): 273-276.

Description: In a glacial erratic at Shippan Point.

Reference: Brown, Samuel C. (1930): Mineral Collecting In Southwestern Connecticut. Rocks & Minerals, vol. 5, no. 1, p. 13.