Lulzacite: Properties and Occurrences

Lulzacite is a strontium-containing phosphate mineral with the chemical formula Sr2Fe2+(Fe2+, Mg)2Al4(PO4)4(OH)10. It is a triclinic-pinacoidal mineral containing aluminum, hydrogen, iron, magnesium, oxygen, phosphorus, and strontium. It occurs there as a dark grey to green granular aggregates within an Ordovician quartzite.

It was named for the discoverer of the mineral, Y. Lulzac. Found only at the type locality at the Bois-de-la-Roche quarry in Pays de Loire in France.

General Information

  • Category: Phosphate minerals
  • Formula: Sr2Fe2+(Fe2+,Mg)2Al4(PO4)4(OH)10
  • Crystal system: Triclinic
  • Crystal class: Pinacoidal (1)
  • Color: Grayish-green to yellowish-green.

Properties

Lulzacite is a very rare, one-locality, strontium – Fe-Al phosphate found with siderite. The Lulzacite is the glassy bluish grey, compact and massive areas on this specimen.

  • Crystal habit: Anhedral aggregates; rarely small euhedral crystals
  • Cleavage: None
  • Mohs scale hardness: 5.5–6
  • Luster: Vitreous
  • Diaphaneity: Transparent–translucent
  • Specific gravity: 3.55
  • Optical properties: Biaxial (−)

Occurrences

It occurs in veins of quartz and siderite, with pyrite, apatite, and goyazite.

The mineral was first described in 2000 from quartzite deposits (47°42′50″N 1°29′20″W) at Saint-Aubin-des-Châteaux, Loire-Atlantique, France, and is named after Y. Lulzac, a French geologist who discovered the mineral. In this deposit, lulzacite occurs within quartz and siderite veinlets at quartzite–limestone contacts. Other minerals found in the veinlets include apatite, goyazite, and pyrite.

 

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