Cathodoluminescence (CL) behaviour and crystal chemistry of apatite from rare-metal deposits

AbstractApatite samples from rare-metal mineralization were investigated by a combination of cathodoluminescence (CL) microscopy and spectroscopy, microchemical analysis and trace element analysis. Internal structures revealed by CL can be related to variations in the crystal chemistry and may sometimes reflect changes in the composition of the mineralizing fluids.Apatite from mineralization related to alkaline rocks and carbonatites (Type 1) typically exhibits relatively homogeneous blue and lilac/violet CL colours due to activation by trace quantities of rare earth element ions (Ce3+, Eu2+, Sm3+, Dy3+ and Nd3+). These results correlate with determined trace element abundances, which show strong light rare earth element (LREE) enrichment for this type of apatite. However, a simple quantitative correlation between emission intensities of REE3+/2+ and analysed element concentrations was not found.Apatite from P-rich altered granites, greisens, pegmatites and veins from Sn-W deposits (Type 2) shows strong Mn2+-activated yellow-greenish CL, partially with distinct oscillatory zoning. Variations in the intensity of the Mn2+-activated CL emission can be related either to varying Mn/Fe ratios (quenching of Mn activated CL by Fe) or to self-quenching effects in zones with high Mn contents (>2.0 wt.%). The REE distribution patterns of apatite reflect the specific geological position of each sample and may serve as a “tracer” for the REE behaviour within the ore system. Although the REE contents are sometimes as high as several hundred parts per million, the spectral CL measurements do not exhibit typical REE emission lines because of dominance of the Mn emission. In these samples, REE-activated luminescence is only detectable by time-resolved laser-induced luminescence spectroscopy.Both types of apatite (Type 1 in the core and Type 2 in the rim) were found in single crystals from the Be deposit Ermakovka (Transbaikalia). This finding proves the existence of two stages of mineralization within this deposit.

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Analyses of historic U.S. Bureau of Mines samples for geochemical trace-element and rare-earth-element data from the Zane Hills pluton, northwestern Alaska

10.14509/27296 ◽

2014 ◽

Author(s):

M. B. Werdon ◽

M. J. Blessington

Keyword(s):

Rare Earth ◽

Trace Element ◽

Rare Earth Element ◽

Earth Element ◽

Element Data

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Zircon U-Pb age, Trace Element, and Hf Isotopic Compositions of Nordmarkite in the Lizhuang Rare Earth Element Deposit in the Western Margin of the Yangtze Block

Acta Geologica Sinica - English Edition ◽

10.1111/1755-6724.13503 ◽

2018 ◽

Vol 92 (1) ◽

pp. 225-240 ◽

Cited By ~ 2

Author(s):

Jiayun ZHOU ◽

Hongqi TAN ◽

Daxin GONG ◽

Zhimin ZHU ◽

Liping LUO

Keyword(s):

Rare Earth ◽

Trace Element ◽

Rare Earth Element ◽

Earth Element ◽

Yangtze Block ◽

Western Margin ◽

Isotopic Compositions

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Rare Earth Element and Trace Element Features of Gold-bearing Pyrite in the Jinshan Gold Deposit, Jiangxi Province

Acta Geologica Sinica - English Edition ◽

10.1111/j.1755-6724.2010.00077.x ◽

2010 ◽

Vol 84 (3) ◽

pp. 614-623 ◽

Cited By ~ 13

Author(s):

Guangzhou MAO ◽

Renmin HUA ◽

Jianfeng GAO ◽

Kuidong ZHAO ◽

Guangming LONG ◽

...

Keyword(s):

Rare Earth ◽

Trace Element ◽

Gold Deposit ◽

Rare Earth Element ◽

Earth Element ◽

Jiangxi Province ◽

Gold Bearing

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Analyses of historic U.S. Bureau of Mines samples for geochemical trace-element and rare-earth-element data from the Porcupine River drainage, northeastern Alaska

10.14509/27298 ◽

2014 ◽

Author(s):

M. B. Werdon ◽

M. J. Blessington

Keyword(s):

Rare Earth ◽

Trace Element ◽

Rare Earth Element ◽

Earth Element ◽

River Drainage ◽

Element Data

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Rare metal indicator minerals in bedrock and till at the Strange Lake peralkaline complex, Quebec and Labrador, Canada

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2018-0299 ◽

2019 ◽

Vol 56 (8) ◽

pp. 857-869

Author(s):

M.B. McClenaghan ◽

R.C. Paulen ◽

I.M. Kjarsgaard

Keyword(s):

Rare Earth ◽

Specific Gravity ◽

Rare Earth Element ◽

Earth Element ◽

Rare Metal ◽

Heavy Mineral ◽

Surficial Sediments ◽

Heavy Rare Earth ◽

Heavy Rare Earth Element ◽

Indicator Minerals

A study of rare metal indicator minerals and glacial dispersal was carried out at the Strange Lake Zr – Y – heavy rare earth element deposit in northern Quebec and Labrador, Canada. The heavy mineral (>3.2 specific gravity) and mid-density (3.0–3.2 specific gravity) nonferromagnetic fractions of mineralized bedrock from the deposit and till up to 50 km down ice of the deposit were examined to determine the potential of using rare earth element and high fileld strength element indicator minerals for exploration. The deposit contains oxide, silicate, phosphate, and carbonate indicator minerals, some of which (cerianite, uraninite, fluorapatite, rhabdophane, thorianite, danburite, and aeschynite) have not been reported in previous bedrock studies of Strange Lake. Indicator minerals that could be useful in the exploration for similar deposits include Zr silicates (zircon, secondary gittinsite (CaZrSi2O7), and other hydrated Zr±Y±Ca silicates), pyrochlore ((Na,Ca)2Nb2O6(OH,F)), and thorite (Th(SiO4))/thorianite (ThO2) as well as rare earth element minerals monazite ((La,Ce,Y,Th)PO4), chevkinite ((Ce,La,Ca,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22), parisite (Ca(Ce,La)2(CO3)3F2), bastnaesite (Ce(CO3)F), kainosite (Ca2(Y,Ce)2Si4O12(CO3)·H2O), and allanite ((Ce,Ca,Y)2(Al,Fe)3(SiO4)3(OH)). Rare metal indicator minerals can be added to the expanding list of indicator minerals that can be recovered from surficial sediments and used to explore for a broad range of deposit types and commodities that already include diamonds and precious, base, and strategic metals.

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