mineral specimens
rare minerals
mineral dealer
systematic minerals
Black Hills minerals
fine minerals
mineral dealer
Dana minerals
IMA minerals
mineral collections
rock and minerals
gem crystal
0 item @ $0.00  

Mineralpedia Details for Macfallite

Reset

Macfallite

Macfallite

Name in honor of Russell P. MacFall who was an American amateur mineralogist and author. Macfallite is a rare mineral that can be found only in the United States at the Manganese mine in Michigan which is its type locality, at the Wasaka mine in Hokkaido, Japan, and at the Cerchiara mine in Liguria, Italy.  It occurs in abundance in Michigan replacing calcite in lenses and fissures in basalt and replacing braunite in low temperature metamorphic conditions in Italy.

Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/macfallite.pdf

Formula
Ca2Mn3+3(SiO4)(Si2O7)(OH)3 
Crystal System
Monoclinic 
Crystal Habit
Acicular, Aggregates, Twinning Common 
Cleavage
Perfect, None, None 
Luster
Vitreous - Silky 
Color
brown, maroon, reddish brown, pink 
Streak
brown 
Class
Monoclinic - Prismatic 
Hardness
5-5.5 
WebMineral
View Macfallite 
Mindat
View Macfallite 

Macfallite from Manganese mine, Copper Harbor, Keweenaw Co., Michigan, United States

Macfallite
            from Manganese mine, Copper Harbor, Keweenaw Co., Michigan, United States

Deep brownish red, compact, radial crystals to 1mm in matrix with darker brown Orientite. Both mineral replaced Calcite.

Click thumbnail images for larger view.

Macfallite from Artur mine, Jaguaracu, Minas Gerais, Brazil

Macfallite
            from Artur mine, Jaguaracu, Minas Gerais, Brazil

Less than 1mm maroon crystals suspended as inclusions in Quartz.

Click thumbnail images for larger view.

All photos by Dakota Matrix and are Copyrighted © and may not be used without permission. Copyright © 2019 - Dakota Matrix Minerals, Inc. Privacy | Terms & Conditions | Site Map