Mineralpedia Details for Bastnasite-(Ce)

Named for the type locality at the Bastnas mines in Vastmanland, Sweden and for the dominance of cerium over the other rare earth elements in the composition. Bastasite-Ce is an uncommon mineral, but is the most common rare earth bearing mineral. It is usually a hydrothermal mineral although it is possible to be a primary mineral as well. It can be found in granite, alkali syenites and pegmatites, carbonatites, contact metamorphic deposits, and as a detrital mineral in placer deposits. Localities include in, additionally, France, Turkey, Afghanistan, Pakistan, Madagascar, Burundi, Zambia, the United States, Canada, China, and several others. Bastnasite-Ce has a dark red cathodoluminescence. It is strongly piezoelectric and generated a charge in response to pressure.

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

Formula

CeCO₃F 

Crystal System

Hexagonal 

Crystal Habit

Prismatic, Massive - Granular 

Cleavage

Imperfect, Indistinct, None 

Luster

Vitreous - Greasy 

Color

yellow, reddish brown 

Streak

white 

Class

Hexagonal - Ditrigonal Dipyramidal 

Fracture

Uneven 

Hardness

4-5 

WebMineral

View Bastnasite-(Ce) 

Mindat

View Bastnasite-(Ce) 

A cluster of flat, very short prismatic crystals with beveled edges representing the pyrimidal faces. The largest crystal of the group is 1.2cm across. There are a few Aegerine needles attached to the crystals.

This specimen features three crystals to 1.2 and 1cm with the third only exposed as a termination. There are in two other crystals; one is shown as a tiny 2mm crystal in front. The other is exposed on the backside. All are terminated with slight beveled edges and are reddish brown and glassy with good luster. The matrix is the actual country rock of what is called the "High Himalayan Crystalline Zone", which is a gneissic alkaline granite composed of microcline, aegeriene, riebeckite and quartz.

A large Bastnasite crystal to 1.6cm, terminated with beveled edges in alkaline riebeckite rich granite matrix.

Deep red glassy prismatic crystal to 1.8cm with complex termination.

Deep red, hexagonal crystal with complex termination - 1.6cm.

Pervasive brownish red grains suspended in matrix.

An incredibly large, deep red prismatic crystal to 4cm, terminated with a smaller 2cm crystal adjoined at the side also terminated. Contains unknown inclusions. This is the premier locality for this species.

Very rich specimen loaded with brown, massive Bastnasite from this world class REE deposit.

Possibly one of the best localities for Bastnasite. A superb, well crystallized rosette 1cm across. Ex. Kay Robertson & Scott Williams collection. See Prov. tab.

Dark root beer colored thick plates.