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Mineral Environments
- Unaltered Pegmatites -

     "The pegmatites, which are the residual portion of the magma and the last to have crystallized, can take the form of dikes, pipes and lenses. They appear to have no continuation at depth. Many of them pinch and swell irregularly from a few centimeters to a meter or more in width. Where the pegmatites swell, open cavities occur with well formed crystals growing in the cores. Included under pegmatites are small, coarse grained patches and segregations in nepheline syenite".*

     "The syenitic pegmatites of MSH generally are rich in sodium silicates and rare element minerals" (Table a - Unaltered pegmatites). "The most common minerals of the pegmatites are microcline and aegirine with local concentration of analcime, serandite and catapleiite. Many of the pegmatites are altered in varying degrees, probably by hydrothermal action. These are characterized by manganese oxides, chlorites, sulfides and other minerals" (Table b - Altered pegmatites).*

Table a - Minerals found in unaltered pegmatites
Aegirine
Albite
Analcime
Anatase
Ancylite-(Ce)
Annite
Arfvedsonite
Astrophyllite
Barylite
Bastnäsite-(Ce)
Behoite
Biotite
Calcio-ancylite-(Ce)
Calcite
Catapleiite
Cerite-(Ce)
Chamosite
Donnayite-(Y)
Elpidite
Epididymite
Epistolite
Eryhtrite
Eudialyte

Eudidymite
Fluorapatite
Fluorite
Gaidonnayite
Galena
Genthelvite
Gobbinsite
Gonnardite
Greigite
Hedenbergite
Kupletskite
Kutnohorite
Leifite
Leucophanite
Mangan-neptunite
Microcline
Monteregianite-(Y)
Natrolite
Neighborite
Nenadkevichite
Nepheline
Paranatrolite
Parisite-(Ce)
Penkvilskite
Perraultite
Phillipsite
Polylithionite
Pyrite
Pyrochlore
Pyrophanite
Pyrrhotite
Raite
Rhabdophane-(Ce)
Rhodochrosite
Rinkite
Senaite
Sérandite
Sphalerite
Steacyite
Tundrite-(Ce)
Vinogradovite
Willemite
Wurtzite
Xenotime-(Y)

* From Mineralogical Record Vol 21, Horváth L. and Gault R.A.