Akopovaite

akopovaite

Images

Formula: Al4Li2(OH)12(CO3)(H2O)3
Carbonate, hydrotalcite supergroup, lithium-bearing mineral
Crystal system: Monoclinic
Specific gravity: 2.12 measured, 2.14 calculated
Hardness: 1
Colour: White or yellowish
Luminescence: Luminescent with a weak bluish-greenish colour after excitation with a mercury quartz lamp with both short wave (254 nm) and medium wave (365 nm) filters and with green after excitation with a nitrogen laser (λex = 337.1 nm) (Mindat).
Solubility: easily soluble both in concentrated and diluted (up to 0.5 vol. %) hydrochloric and nitric acid followed by the release of CO2 (Mindat).
Environments

Pegmatites
Metamorphic environments

Akopovaite is a relatively new mineral, approved in 2018.

Localities

At the Monte Copello-Reppia mine, Reppia, Ne, Genoa, Liguria, Italy, radial aggregates of white prisms of akopovaite with a silky lustre have been found lying on serpentinite (Mindat photo).
Akopovaite from the Monte Copello-Reppia mine - Image

At the Akopovaite type locality, Asan-Usun glacier, Karasu-Karavshinskoye, Turkestan Ridge, Batken Region, Kyrgyzstan, akopovaite has been found in a zoned spodumene-bearing pegmatite vein associated with quartz-micaceous schists. It occurs as a hydrotalcite supergroup mineral in white or pale yellowish rosette-like aggregates that are composed of tiny curved plates up to 30 μm in size, associated with gibbsite, quartz, albite, microcline, muscovite, montebrasite, siderite, schorl and birnessite-like Fe–Mn oxides. Akopovaite has one perfect cleavage and is transparent and very soft. Akopovaite is the first naturally occurring hydrotalcite supergroup carbonate species of Al and Li; its synthetic analogue is known (MM 84.2.301-311, HOM).
Akopovaite from the Asan-Usun glacier - Image

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