hemihedral

[ hem-i-hee-druh l ]

/ ˌhɛm ɪˈhi drəl /

(of a crystal) having only half the planes or faces required by the maximum symmetry of the system to which it belongs.

Origin of hemihedral

First recorded in 1830–40; hemi- + -hedral

hem·i·he·dral·ly, adverb

The occurrence of hemihedral faces was considered by Pasteur to be a sufficient criterion for an optically active substance.

The Phase Rule and Its Applications |Alexander Findlay
In this way a mixture of the two asparagines was obtained, which were separated by picking out the hemihedral crystals.

Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 7 |Various
These systems, however, only represented holohedral forms, leaving the hemihedral and tetartohedral classes to be explained.

Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 |Various
In this species the hemihedral variety, Hemiaspis, often occurs.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) |Ernst Haeckel

It may be considered as the hemihedral form of the ditetragonal bipyramid.

Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 |Various

hemihedral

/ (ˌhɛmɪˈhiːdrəl) /

(of a crystal) exhibiting only half the number of planes necessary for complete symmetry