scalenohedron


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Related to scalenohedron: rhombohedron, Pyritohedron

scalenohedron

(ˌskeɪliːnəˈhiːdrən)
n, pl -drons or -dra (-drə)
a pyramidal form of the rhombohedral system in which the faces form scalene triangles
References in periodicals archive ?
Calcite crystals occur in a wide variety of habits, the scalenohedron and rhombohedron being the most common forms.
Crystal habits range from elongated hexagonal prisms with low-angle rhombohedron terminations to prism and scalenohedron combinations in varying proportions.
It occurs in a wide variety of habits, but the scalenohedron and rhombohedron are the most common forms.
According to Kostov (1968) and Moroshkin and Frishman (2001), the temperature of crystallization of various calcite forms proceeds from the {10[bar.1]1} rhombohedron at high temperature to the {[bar.1][bar.1]20} prism, {21[bar.3]1} scalenohedron, and lastly the {02[bar.1]1} steep rhombohedron at low temperature.
Forms like the scalenohedron can be generated by stacking tiny rhombohedrons in a certain way.
obtuse rhombohedron-- flattened III {h0-h1} obtuse rhombohedron colorless to white, locally coated "pseudocubic" with brown iridescent material IV {h0-h1} obtuse rhombohedron colorless V globular clusters white VI {hk-il} acute scalenohedron colorless to white VII {hk-i1}, {h0-h1} obtuse colorless to white scalenohedron modified by obtuse rhombohedron Quarries Where Type Crystal Forms Color (UV) Observed* I {h0-h1} obtuse rhombohedron yellow BG, PL "pseudocubic" II {h0-h1}, {0k-k1} pos.
Microsparite and sparite calcite crystals are mostly equant to elongated rhombohedrons or scalenohedrons, but also a few prismatic crystals were observed.
The big calcite crystals are highly lustrous and limpidly colorless and transparent; some are fat scalenohedrons while others are face-rich, complex, nearly equant forms of generally rhombohedral aspect.
It forms crusts of white opaque or colorless to yellow transparent scalenohedrons and other crystal habits, usually less than 2 cm long and commonly exhibiting an orange fluorescence.
Calcite from the locality forms clean, pretty, compound "dogtooth" crystals composed of scalenohedrons in parallel growth, pale orange and translucent and reaching 5 cm; matrix specimens reach 10 cm.
The manganese-tinted calcite in these pieces forms highly lustrous, translucent to transparent, very pale pinkish purple, twinned scalenohedrons reaching 25 cm long.
They show hollow, pointed triangular shapes which very probably are molds after calcite scalenohedrons. The molds are composed of tiny black sphalerite crystals mixed with larger galena crystals up to 5 mm, coated by tin-white arsenopyrite crystals on their inner surfaces.