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|System:||Monoclinic||Colour:||Green, blue, blackish ...|
|Name:||Named in 1925 by Charles Palache and Helen E. Vassar in honor of US geologist, Raphael Pumpelly [September 8, 1837 Owego, New York, USA – August 10, 1923 Newport, Rhode Island, USA]. The chemical suffix was added in 1973 by the IMA. Pumpelly was an active mining consultant and was professor of Mining Science at Harvard University. He was appointed director of the New England branch of the U. S. Geological Survey in 1884.|
Classification of Pumpellyite-(Mg)
|Strunz 8th edition ID:||8/C.24-30|
|Nickel-Strunz 10th (pending) edition ID:||9.BG.20|
9 : SILICATES (Germanates)
B : Sorosilicates
G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral  and greater coordination
|Dana 8th edition ID:||18.104.22.168|
58 : SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
2 : Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in  and higher coordination; single and double groups (n = 1, 2)
|Hey's CIM Ref.:||16.11.7|
16 : Silicates Containing Aluminum and other Metals
11 : Aluminosilicates of Ca and Mg with or without alkalis
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Type Occurrence of Pumpellyite-(Mg)
|Type Locality:||Keweenaw Co., Michigan, USA|
Physical Properties of Pumpellyite-(Mg)
|Colour:||Green, blue, blackish green, brown|
Crystallography of Pumpellyite-(Mg)
Optical Data of Pumpellyite-(Mg)
|RI values:||nα = 1.674 - 1.748 nβ = 1.675 - 1.754 nγ = 1.688 - 1.764|
|2V:||Measured: 70° to 90°, Calculated: 32° to 76°|
|Maximum Birefringence:||δ = 0.014 - 0.016|
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Chemical Properties of Pumpellyite-(Mg)
|Simplified for copy/paste:||Ca2MgAl2(Si2O7)(SiO4)(OH)2·H2O|
|Essential elements:||Al, Ca, H, Mg, O, Si|
|All elements listed in formula:||Al, Ca, H, Mg, O, Si|
Relationship of Pumpellyite-(Mg) to other Species
|Series:||Forms a series with Julgoldite-(Fe2+) (see here)|
Forms a series with Pumpellyite-(Fe2+) (see here)
|Member of:||Pumpellyite Group|
|Other Members of Group:|
|Related Minerals - Nickel-Strunz Grouping):|
|Related Minerals - Hey's Index Grouping:|
Other Names for Pumpellyite-(Mg)
|Health Warning:||No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.|
References for Pumpellyite-(Mg)
American Mineralogist (1925): 10: 412-418.
American Mineralogist (1976): 61: 176-177.
American Mineralogist (1983): 68: 1250.
American Mineralogist (1985): 70: 1011.
American Mineralogist (1992): 77: 1307-1308.
Internet Links for Pumpellyite-(Mg)
Localities for Pumpellyite-(Mg)
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
(TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.