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Formula: Ca2(Al2Sc)(Si2O7)(SiO4)O(OH)
Sorosilicate (Si2O7 groups), epidote group,
epidote supergroup,
scandium-bearing mineral
Crystal System: Monoclinic
Specific gravity: 3.537 calculated for the empirical formula
Hardness: 6
Streak: White
Environments
Heflikite is a new mineral, approved in 2023 and to date (October 2024) reported only from the type
localities
Localities
There are two co-type localities, the Heftetjern pegmatite, Tørdal, Drangedal, Telemark, Norway, and the Jordanów
serpentinite quarry, Gmina Jordanów Śląski, Wrocław County, Lower Silesian Voivodeship, Poland.
The Heftetjern pegmatite, Tørdal, Drangedal, Telemark, Norway, is widely known for
scandium mineralisation hosted in the
granitic
cleavelandite–amazonite
pegmatite that has relatively high concentrations of
tin, scandium,
beryllium and lithium. The
pegmatite is weakly zoned and consists dominantly of
amazonite and albite with minor
oligoclase, quartz, and a
variety of micas. The main accessory minerals are
beryl, spessartine,
allanite-(Ce),
uedaite-(Ce),
gadolinite-(Y),
cassiterite, scandium-rich
ixiolite, zircon,
monazite-(Ce),
scandium-bearing
pyrochlore supergroup minerals,
milarite and phenakite.
A late-stage mineral assemblage, present mainly in vugs and fractures, comprises
agakhanovite-(Y), bazzite,
bertrandite, bohseite,
cascandite, cerium -
lanthanum – scandium - enriched
epidote–allanite minerals,
yttrium-rich fluorite,
heftetjernite,
manganese-bearing
hellandite-(Y),
scandium-rich helvine, triclinic
Ca-hingganite-(Y) (This lowering of symmetry to an acentric
triclinic system is caused by different element occupancies on the gadolinite supergroup A-site
(https://www.researchgate.net/figure/CHEMICAL-DATA-FOR-Ca-HINGGANITE-Y_tbl1_332933060)),
scandium-rich garnet,
oftedalite, rynersonite,
scandiobabingtonite,
thortveitite,
triclinic titanite and an unnamed new species of OH-dominant analogue of
gadolinite-(Y). Heflikite is a part of this late-stage
mineral assemblage, and is associated with scandium-rich
allanite-(Ce), rarely with
allanite-(La) and
hingganite-(Y).
The epidote supergroup minerals from the locality form grey,
green and brown, welldeveloped, transparent crystals and polycrystalline aggregates up to 10 mm in size
(MM 88.228–243).
At the the Jordanów serpentinite quarry, Gmina Jordanów Śląski, Wrocław County, Lower Silesian Voivodeship,
Poland, heflikite was discovered in a granitic
pegmatite consisting mainly of
quartz, sodic plagioclase and
K-feldspar, with accessory pale green
beryl, dark green dravite, and
randomly scattered aggregates of greenish yellow clinochlore. Detailed
investigations also revealed the presence of biotite,
muscovite, spessartine,
titanite, zircon,
cassiterite,
columbite-(Mn), fersmite,
euxenite-(Y),
monazite-(Ce),
xenotime-(Y),
allanite-(Ce), epidote,
clinozoisite,
rhabdophane-(La),
rhabdophane-(Ce),
rhabdophane-(Nd),
pyrochlore group and
microlite group minerals,
phenakite, bavenite,
bertrandite, milarite,
tremolite, diopside,
uraninite, aikinite,
galena, scandium-rich
ixiolite and a few
scandium-bearing silicates, including
cascandite, scandium-rich
actinolite,
scandio-winchite,
kristiansenite, bazzite
and heflikite.
At Jordanów Śląski, heflikite was found in the form of a few compositionally zoned euhedral to subhedral
separate crystals and intergrowths with rare earth element-bearing
clinozoisite and
allanite-(Ce), reaching a maximum of 100 μm in size. Textural
observations indicate that the crystallisation sequence starts with heflikite (core or inner zone of the
aggregates), progresses to scandium-rich
allanite-(Ce),
scandium-rich clinozoisite
and finally to clinozoisite
(MM 88.228–243).
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