Each claim states how it is known and cites its evidence.
EstablishedSample GCG-1, volumetric portions: quartz 70 per cent, zinnwaldite 16 per cent, feldspar 4 per cent, non-differentiated phases 10 per cent. Mean diameter d50,3: quartz 2.65 mm, feldspar 0.95 mm, zinnwaldite 0.75 mm, rock overall 2.23 mm. Zinnwaldite roughness degree 50 per cent. The d50,3 is a VOLUME-WEIGHTED MEDIAN and is not comparable with a maximum or a typical range reported by any other source.
Measured at this deposit
In the Cínovec greisen sample GCG-1 the rock is dominated by quartz with zinnwaldite as the second component and very little feldspar, and its mineral grains are fine by the measure the source uses: a volume-weighted median diameter below a millimetre for the zinnwaldite. Both figures belong to that sample, taken in that campaign, and neither is a property of Cínovec greisen in general.
- assertion basis: SUBJECT_MEASURED
Evidence support: Supported by the cited evidence · one source
Evidence: Durjagina 2026 · Peer-reviewed
EstablishedZinnwaldite-rich greisen GCG-1: quartz 70 per cent by volume, zinnwaldite 16 per cent, lowest point load strength index of about 2 MPa and uniaxial compressive strength of about 53 MPa, ISRM moderate strength. Zinnwaldite-poor greisenized granite GCW-1 of the same deposit: ISRM high strength. Lepidolite-rich ore: finer grains, lower roughness, low clustering, highest compressive strength, more energy-intensive to crush but potentially easier to liberate once ground fine enough.
Two European lithium-mica ores behave oppositely under comminution for reasons that lie in their fabric rather than their mineral names: the ZINNWALDITE-RICH Cínovec greisen is the weakest of the samples studied in compressive strength despite having the highest quartz content, while the Villasrubias lepidolite is finer, smoother, more disseminated and the strongest — so selective comminution cannot be designed from mineral hardness contrasts alone. The zinnwaldite-POOR greisenized granite of the same deposit runs the other way and is classified as high strength, which is why the sample this claim rests on matters as much as the ore type it names.
Evidence support: Supported by the cited evidence · one source
Evidence: Durjagina 2026 · Peer-reviewed
EstablishedAutomated mineralogy of zinnwaldite mineral association shows a displacement of the muscovite–quartz ratio relative to modal mineralogy, indicating good quartz–zinnwaldite boundary breakage and weak muscovite–zinnwaldite breakage.
In comminuted Zinnwald greisen, breakage runs preferentially along quartz–zinnwaldite grain boundaries and poorly along muscovite–zinnwaldite boundaries: the rock comes apart between the lithium mica and the quartz, and not between the lithium mica and the other mica.
Evidence support: Supported by the cited evidence · one source
Evidence: Sandmann 2013 · Peer-reviewed
EstablishedOwn measurement, light microscopy of polished thin sections: zinnwaldite and quartz usually 5 to 6 mm as mineral grain or aggregate size; topaz up to 1 mm; the raw material described as coarse-grained and isotropically textured. CITED, NOT MEASURED HERE: zinnwaldite ranging up to 5 mm in grain size, attributed by the paper to Atanasova, Mineralogy, Geochemistry and Age of Greisen Mineralization in the Li-Sn(-W) Deposit Zinnwald, master's thesis, TU Bergakademie Freiberg, 2012. A typical range and a maximum are two different quantities and neither is a volume-weighted median.
Measured at this deposit
The Zinnwald greisen selected for the comminution study is described by its authors as coarse-grained and isotropically textured, with zinnwaldite and quartz usually at mineral grain or aggregate sizes of 5 to 6 millimetres by light microscopy of polished thin sections, and topaz ordinarily smaller at up to 1 millimetre. The frequently quoted figure of ZINNWALDITE UP TO 5 MILLIMETRES IS NOT THIS STUDY'S OWN MEASUREMENT: the paper cites it to a 2012 master's thesis, and this corpus records it as that thesis's number carried forward rather than as characterization by the citing study.
- assertion basis: SUBJECT_MEASURED
Evidence support: Supported by the cited evidence · one source
Evidence: Sandmann 2013 · Peer-reviewed