Ferri-winchite (original) (raw)

RI values:

_n_α = 1.670(2) _n_β = 1.680(5) _n_γ = 1.685(6)

δ = 0.015

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Optical Extinction:

Z = b, optic plane ⊥ (010).

Comments:

Perpendicular to bc plane = bright brownish yellow; Y = lilac; Z = dark blue.

Comments:

Absorption: c = b > ⊥bc;

General Appearance of Type Material:

Place of Conservation of Type Material:

Natural Science Museum of the Ilmen Preserve, Urals Division of the Russian Academy of Sciences, Miass, Russia, #8987.

Geological Setting of Type Material:

Veins cross-cutting pyroxene fenites.

Associated Minerals at Type Locality:

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.