|Latitude & Longitude (WGS84):||44° 16' 9'' North , 70° 28' 23'' West|
|Latitude & Longitude (decimal):||44.26944,-70.47306|
|Köppen climate type:||Dfb : Warm-summer humid continental climate|
Granite pegmatite in the Oxford pegmatite field. Mount Mica is the second oldest elbaite occurrence in North America, after Clarkes Ledge Quarry, Chesterfield, Massachusetts (King, 2010; King and Teixeira, 2010). Mount Mica was found in October 1821 by two professional men: one a doctor of medicine, Ezekiel Holmes, and one a lawyer, Elijah Hamlin. The day following the discovery was marked by a surprise early snowfall preventing further exploration until Hamlin's younger brothers drilled and blasted the ledge in the summer of 1822.(Although there are numerous reports which cite Augustus Hamlin's histories of the locality claiming an 1820 discovery, the date is incorrect for many reasons and the actual snowfall date is now known (Sturtevant, 1948; Perham, 1987, King, 2000, 2001, 2006a,b, 2012). Analysis of snowfall records made by Parker Cleveland as well as a search of Oxford County town histories corroborate Sturtevant (1948) and Perham (1987) and point to October 18, 1821, as the day of the discovery of Mount Mica and the famous snowstorm covering Mount Mica until the spring (King, 2012). Mount Mica is an LCT-class granite pegmatite.
The first Rose Quartz crystals known in the world were found at Mount Mica Quarry about 1913-1915. The second locality for genuine rose quartz crystals in the world, the Dunton Gem Quarry, Newry, produced its first crystals in 1927. A third world locality was discovered in 1942, at the Rose Quartz Crystal locality, also in Newry. Rose Quartz crystals were not known in Brazil until 1958.
It is particularly interesting that some pink Mount Mica tourmaline fluoresces blue in short-wave ultraviolet light, but that property is not so widespread at Mount Mica as the very fluorescent tourmaline of the Dunton Quarry, Newry (q.v.). Fluorescence is not a property that can be unambiguously used to differentiate genuine Mount Mica tourmaline from mislabeled Mount Mica tourmaline, but there may be useful comparisons when known and suspected specimens are examined at the same time.
Local rocks include Silurian Sangerville Formation Anasagunticook member.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
66 valid minerals. 3 (TL) - type locality of valid minerals. 11 erroneous literature entries.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
252.17 - 541 Ma
|Paleozoic sedimentary rocks|
Age: Paleozoic (252.17 - 541 Ma)
Lithology: Sedimentary rocks
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
433.4 - 443.8 Ma
|Silurian Sangerville Formation, Anasagunticook member|
Age: Llandovery (433.4 - 443.8 Ma)
Stratigraphic Name: Anasagunticook Member
Description: Silurian Sangerville Formation Anasagunticook member
Comments: In western sequence of central Maine trough, divided into a main body, lower member near Woodstock (schist and granofels probably equivalent to member B), upper member near Woodstock (schist and granofels probably equivalent to member C), member A (in turn divided into gray shale and massive sandstone facies, massive sandstone facies, and polymict conglomerate facies), member B (in turn divided into quartz-rich, polymictic conglomerate facies and gray shale and sandstone facies), and member C (in turn divided into quartz conglomerate, sandstone, and gray shale; impure limestone and quartz conglomerate lenses; and upper gray shale and sandstone). (ME004) Unit description from USGS GEOLEX website (ME078). E - Epidote-amphibolite facies; AA - Low rank amphibolite facies; AB - Medium rank amphibolite facies; Protolith H - Lithic sandstone and conglomerate.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.