WGNHS
Wisconsin Geological and Natural History Survey

Ixiolite

Close-up of massive black ixiolite crystal in matrix (tip of red arrow). Okhmyl’k Mt., Voron’i Tundry, Kola Peninsula, Murmanskaja Oblast’ Northern Region, Russia. Ixiolite crystal is 0.15 mm across. Image by Dan Weinrich. (Photo courtesy Dan and Diana Weinrich Minerals; unauthorized reproduction is prohibited.)

Formula: (Ta,Nb,Sn,Fe,Mn)4O8  Orthorhombic

Description:

Massive black ixiolite crystal in matrix (tip of red arrow). From Okhmyl’k Mt., Voron’i Tundry, Kola Peninsula, Murmanskaja Oblast’ Northern Region, Russia. Ixiolite crystal is 0.15 mm across. (Photo courtesy Dan and Diana Weinrich Minerals; unauthorized reproduction is prohibited.)

Ixiolite is a rare dark gray to steel gray mineral found in granite pegmatites.

MARATHON COUNTY: Ixiolite is found as elongated crystals up to 2 mm long in pegmatites at the Koss Pit (SW sec. 2 T.27 N. R.5E.) SW of Rib Mountain (Buchholz, Falster and Simmons, 1999, 2000). It is also tentatively noted from the Maguire Pit in the Ladick Quarry complex (sec. 19 and 20 T. 27N. R.6E.) (Buchholz and Simons, 2002; Buchholz et al., 2004).