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Long Hill quartz locality, Haddam, Middlesex Co., Connecticut, USAi
Regional Level Types
Long Hill quartz locality- not defined -
Haddam- not defined -
Middlesex Co.County

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Latitude & Longitude (WGS84):
41° 27' 14'' North , 72° 30' 25'' West
Latitude & Longitude (decimal):
Köppen climate type:
Nearest Settlements:
East Haddam9,042 (2017)3.8km
Higganum1,698 (2017)6.4km
Moodus1,413 (2017)7.2km
Chester Center1,558 (2017)7.4km
Deep River Center2,484 (2017)9.8km

The west side of Long Hill is host to a quartz crystal deposit where a fault apparently cross-cuts the thin layer of quartzite shown there on the bedrock map of the Haddam quadrangle. These crystals are similar in habit to those found at West Stafford and Moosup, Connecticut, where Mesozoic faults have brecciated quartzite.

It was known as far back as 1825 because it appears on the sketch map by Porter (1825). Williams (1899 and circa 1945) described the locality and crystals accurately: "On the west side of Longhill Quartz crystals can be dug by the bushel.", "in size they are from an inch to ten inches in length often aggregated laterally into groups."

Davis (1901) states: "well defined crystals of large size, translucent, and slightly discolored by oxide of iron, are found loose in the soil. Many of the smaller crystals are doubly terminated and perfectly transparent.

Location is very approximate.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

1 valid mineral.

Detailed Mineral List:

Formula: SiO2
Habit: elongated 6-sided prisms with rhombohedral terminations. Larger crystals tend to be subparallel aggregates with myraid small terminations along the prism faces surrounding one dominant central termination.
Colour: clear to white
Reference: Williams (circa 1945 and 1899); Harold Moritz collection

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides

List of minerals arranged by Dana 8th Edition classification

Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si

List of minerals for each chemical element

O QuartzSiO2
Si QuartzSiO2


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Porter, T. D. (1825), T. D. Porter's Localities of Minerals on Connecticut River. American Journal of Science series 1: 9: 177 and figure at end plate.
Williams, Horace S. (1899), Letter to Miss Eveline Brainerd of Haddam, February 18, 1899. Brainerd Public Library, Haddam, Connecticut.
Davis, James W. (1901), The Minerals of Haddam, Connecticut Mineral Collector: 8(4): 50-54.
Davis, James W. (1901), The Minerals of Haddam, Connecticut Mineral Collector: 8(5): 65-70.
Williams, Horace S. (1945 [circa]), Article for New York Society of Mineralogists. Brainerd Public Library, Haddam, Connecticut.

Other Regions, Features and Areas containing this locality

North America PlateTectonic Plate

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