Pyrochlore

Calcium Sodium Niobium Oxide Hydroxide Fluoride
(Ca, Na)₂Nb₂O₆(O, OH, F)

Pyrochlore is a niobate of calcium, cerium, and other bases. It generally occurs in octahedrons of a yellowish or brownish color and resinous luster. It crystallizes in the isometric symmetry class forming fine octahedral crystals being typically and characteristically modified by other isometric forms.

Pyrochlore usually contains a substantial amount of radioactive elements which produces radioactivity in the mineral. It is a member of informal group of minerals, Rare Earth Oxides and is called Rare Earths. Pyrochlore is sometimes difficult to distinguish, but its octahedral crystal act as an indicator.

Lighter pyrochlore is found in unusual igneous rock, carbonatite and alkalic pegmatites called nepheline syenites. Some of the variety names of pyrochlore are Hatchettolite and ellsworthite. Both contains uranium and occur in the same location, like albeit different mines in the Hybla area of Hastings County, Ontario, Canada.

Physical Properties of Pyrochlore

Color	Yellow, reddish-brown, red or black.
Luster	It can vary from vitreous, adamantine, greasy to resinous.
Transparency	Crystals are translucent with darker specimens being opaque.
Cleavage	In four directions (octahedral), but is indistinct.
Fracture	Conchoidal to uneven.
Hardness	5 - 5.5
Specific gravity	Approximately 3.5 - 4.6 (heavy for non-metallic).
Streak	Pale yellow to brown.

Associated Minerals of Pyrochlore

• Calcite
• Feldspars
• Apatite
• Zircon
• Biotite

Occurrences of Pyrochlore

• Veshnovorgorsk and Chelyabinsk Oblast in Russia
• Mbeya, Tanzania
• St. Peter's Dome, El Paso County, and Colorado in the US
• Brevik, Norway, and Alno in Sweden
• Oka, Quebec and Hastings County, and Ontario in Canada