hemihedral

American  

[hem-i-hee-druhl] / ˌhɛm ɪˈhi drəl /

adjective

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

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hemihedral British  

/ ˌhɛmɪˈhiːdrəl /

adjective

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

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Other Word Forms

• hemihedrally adverb

Etymology

Origin of hemihedral

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

Example Sentences

They crystallize in two complementary hemihedral forms, which are respectively right-handed and left-handed, i.e. enantiomorphous forms.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

All the forms are pedions, each consisting of a single plane; they are thus hemihedral with respect to crystals of the last class.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

Crystals belonging to many of the hemihedral and tetartohedral classes of the six systems of crystallization are devoid of a centre of symmetry.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

These systems, however, only represented holohedral forms, leaving the hemihedral and tetartohedral classes to be explained.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various

The remaining simple forms are “hemihedral with parallel faces,” and from the corresponding holohedral forms two hemihedral forms, a positive and a negative, may be derived.

From Encyclopaedia Britannica, 11th Edition, Volume 7, Slice 7 "Crocoite" to "Cuba" by Various