Loveringit

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Loveringit
General and classification
other names

IMA 1977-023

chemical formula (Ca, Ce) (Ti, Fe, Cr, Mg) 21 O 38
Mineral class
(and possibly department)
Oxides and hydroxides
System no. to Strunz
and to Dana
4.CC.40 ( 8th edition : IV / C.09)
05/08/01/02
Crystallographic Data
Crystal system trigonal
Crystal class ; symbol 3
Room group (no.) R 3 (No. 148)
Lattice parameters a  = 10.337  Å ; c  = 20.667 Å Please complete the source as an individual reference!
Formula units Z  = 3 Please complete the source as an individual reference!
Physical Properties
Mohs hardness 5
Density (g / cm 3 ) 4.42
Cleavage is missing
colour black, white to off-white in reflected light
Line color iron gray
transparency opaque
shine metallic to submetallic

Loveringite is a very rare mineral from the mineral class of oxides and hydroxides . It crystallizes in the trigonal crystal system with the chemical composition (Ca, Ce) (Ti, Fe, Cr, Mg) 21 O 38 and forms irregular, sometimes needle-shaped crystals of up to 120 μm in size and black in color as well as inclusions in other minerals.

Etymology and history

The mineral was first in 1978 by Bryan M. Gatehouse, Ian E. Gray, Ian H. Campbell and Patrick Kelly in the Jimberlana intrusion at Norseman in Western Australia ( Australia found). They named it after the Australian geochemistry professor John Francis Lovering .

classification

In the old (8th edition) and new systematics of minerals according to Strunz (9th edition) , the loveringite belongs together with Cleusonite , Crichtonite , Davidit- (Ce) , Davidit- (La) , Davidit- (Y) , Dessauit- (Y) , gramaccioliite- (Y) , landauite , lindsleyite , mathiasite and senaite to the division of oxides with a ratio of metal to oxygen of 2: 3. The new Strunz'sche mineral classification, however, subdivides here more precisely according to the size of the cations involved and the mineral is therefore now accordingly in the sub-section “With large and medium-sized cations”.

The systematics of minerals according to Dana , which is common in the English-speaking world , assigns loveringite with cleusonite and the other minerals to the crichtonite group, a subgroup of the complex oxides with niobium , tantalum and titanium .

Education and Locations

Loveringite crystallizes late in igneous differentiation into pyroxene and olivine . Depending on where it was found , it is associated with quartz , potassium feldspar , phlogopite , enstatite , baddeleyite , apatite , zirconium , titanite , rutile , ilmenite and chromite or rutile, pseudobrookite , ilmenite, zirconolite , spinel , pargasite and phlogopite.

So far (as of November 2010) seven locations where the loveringit was found are known. In addition to the type locality , Loveringit was found in Laouni in Ahaggar ( Algeria ), in the Hüttwinkl Valley near Rauris in Austria , on the Kerguelen , Bracco in Italy , the Chibinen in Russia and Chiradzi in Zimbabwe .

Crystal structure

Loveringite crystallizes in the trigonal crystal system in the space group R 3 (space group no. 148) with the lattice parameters a = 10.337  Å and c = 20.667 Å as well as three formula units per unit cell . It is isostructural with Senaite and Crichtonite.

See also

Individual evidence

  1. a b Loveringit at mindat.org (engl.)
  2. PR Kelly, IH Campbell, IE Gray, BM Gatehouse: Additional data on loveringite (Ca, REE) (Ti, Fe, Cr) 21 O 38 and mohsite discredite. In: Canadian Mineralogist. 1979, 17, 635-638 ( abstract ; PDF; 647 kB).
  3. ^ Bryan M. Gatehouse, Ian E. Gray, Ian H. Campbell and Patrick Kelly: The crystal structure of loveringite-a new member of the crichtonite group. In: American Mineralogist. 1978, 28, pp. 28-36.
  4. ^ New Dana Classification of Oxide Minerals
  5. ^ Loveringit in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101.

literature

  • Loveringit in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( PDF 70.7 kB )
  • Bryan M. Gatehouse, Ian E. Gray, Ian H. Campbell and Patrick Kelly: The crystal structure of loveringite-a new member of the crichtonite group. In: American Mineralogist. 1978, 28, pp. 28-36 ( full text, pdf ).

Web links