Dunton Gem Quarry, Newry, Oxford Co., Maine, USA
|Latitude & Longitude (WGS84):||44° 32' 34'' North , 70° 43' 23'' West|
|Latitude & Longitude (decimal):||44.5427777778, -70.7230555556|
Granite pegmatite. This is a LCT class granite pegmatite. The mineral list below also contains species from chlorite/actinolite schist host rocks. Hall's Ridge, Plumbago-Puzzle Mountain - Oxford pegmatite field. Land currently owned by Plumbago Timber and Quarries LLC which permitted use of new mineral discovery information to appear on mindat.
Discovered in 1898 by Henry C. Hall who was the brother-in-law of the landowner, Joshua Abbott. Property obtained by International Paper Company in 1898. Leased to Hollis C. Dunton and partners 1902-1904, perhaps until 1905. leased by General Electric Corporation in 1926-1930, with Wallace Dickerson "Dick" Nevel as superintendent. George Crooker worked for Nevel in 1926-1927. Leased briefly by Harvard University in 1949. Leased briefly in 1966 by Richard "Dick" Robinson of Pennacook, New Hampshire. leased by Plumbago Mining Corporation 1972-1977. Leased by Joseph "Joey" Martin 1985-1989. Leased by American Tourmaline Fields from 1989-1996. Purchased by Plumbago Timber and Quarries LLC in 2004.
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 it's first crystals in 1927. A third world locality was discovered in 1942, at the rose quartz Crystal locality, Newry, by George Crooker. Rose quartz crystals were found at the Nevel Quarry, Newry and in the Red Hill Quarry Group, Rumford, Maine in 1949. Rose quartz crystals were not known in Brazil until 1958.
CAUTION: Because of the high demand and low supply of the very special "Newry" gem tourmaline shades, Namibian tourmaline and Afghani tourmaline sellers, who have gem rough almost matching "Newry" color shades, report that they have brisk sales in Maine and New England. Their explanation is that the stones or rough have a "rare" color that mimics authentic Dunton Quarry tourmaline colors. However, buyer beware! It is more than unlikely to have hundreds or thousands of carats of "rare color" tourmaline in stock! One important feature of genuine gem tourmaline from the Dunton Pegmatite is that almost all of the desirable light shades of pink and green tourmaline have a medium to bright blue-white FLUORESCE in short wave ultraviolet light. This property does not guarantee that the tourmaline in question is genuinely from Newry, but it does limit the mislabeling or "mis-branding" of tourmaline as coming from Newry when it does not.
Beesley (1975) was the first to discover that Dunton Quarry untreated elbaite FLUORESCES "light chalky blue" in short wave ultraviolet light while he reported that heat treating intensifies Dunton Quarry tourmaline's blue-white fluorescence. Heating may occasionally turn the body color of Dunton elbaite colorless, however. Fluorescent tourmaline is uncommon, but not rare and has been observed in localities in Maine, Brazil, Afghanistan, Madagascar, Mozambique and elsewhere. Maine tourmaline appears to have some of the stronger fluorescing tourmaline with the pink body color tourmaline fluorescing brighter than green body color tourmaline. Inclusions are very distinctive in Newry gem tourmaline and inclusions may have three phases. Beesley provided illustrations of the inclusions in Dunton elbaite and suggested that these inclusions could also be used to verify the origin of the Newry tourmaline from mislabeled specimens. The species in Dunton Quarry tourmaline inclusions was not identified, however.
|Devonian - Silurian358.9 - 443.8 Ma||Devonian - Silurian Madrid Formation|
Devonian - Silurian Madrid Formation
Probably named for Madrid, ME. Consists of calcareous quartzite with lime-silicate minerals in middle-grade metamorphic zones. Contains minor amounts of argillaceous rocks and calcareous beds. Sulfides absent or inconspicuous. Quartzite grades upward into Dyer Hill member (new). Age is younger than Parmachenee formation (new). (ME031) Unit description from USGS GEOLEX website (ME078). AA - Low rank amphibolite facies; Protolith M - Calcareous sandstone; interbedded sandstone and impure limestone To avoid digital confusion with Dsm, the map symbol for this unit (DSm) has been changed to DSmd in this file and on the digital map.
|Silurian-Devonian358.9 - 443.8 Ma||Silurian-Devonian sedimentary rocks|
|Silurian419.2 - 443.8 Ma||Silurian sedimentary|
References for regional geology:
Data provided by Macrostrat.org
Garrity, C.P., and Soller, D.R.,. Database of the Geologic Map of North America: adapted from the map by J.C. Reed, Jr. and others (2005). U.S. Geological Survey Data Series 424 .
USGS compilers. State geologic map data. State Maps.
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
103 valid minerals. 3 (TL) - type locality of valid minerals. 5 erroneous literature entries.
Beesley, C. (1975) Dunton Mine Tourmaline: An Analysis. Gems and Gemology, 15: 19-24.
King, Vandall T., 1975, Newry, Maine: A Pegmatite Phosphate Locality, Mineralogical Record, v. 6, p. 189-204.
Dunn, Pete J. and Gaines, Richard V. (1978): Uralolite from the Dunton Gem Mine, Newry, Maine: A second occurrence. Mineralogical Record 9(2), 99-100.
King, Vandall T. (1980) Distribution of Alkali and Alkaline-Earth Elements in a Newry, Maine Pegmatite, privately published, Rochester, New York, pp. 131.
King, Vandall T. and Foord, Eugene E., (1994) Mineralogy of Maine, Descriptive Mineralogy, v. 1, Maine Geological Survey, Augusta, Maine.
King, Vandall T. (ed.) (2000) Mineralogy of Maine, V. 2., Maine Geological Survey, Augusta, Maine.
Moore, Paul B. (2000) Analyses of Primary Phosphates from Pegmatites in Maine and Other Localities, in V. T. King (editor), Mineralogy of Maine. Mining History, Gems, and Geology, Maine Geological Survey, Augusta, Maine, p. 333-336.