any of a group of minerals composed principally of oxides of magnesium, aluminum, iron, manganese, chromium, etc., characterized by their hardness and octahedral crystals.
a mineral of this group, essentially magnesium aluminate, MgAl 2 O 4 , some varieties being used as gems.
any of a group of hard glassy minerals of variable colour consisting of oxides of aluminium, magnesium, chromium, iron, zinc, or manganese and occurring in the form of octahedral crystals: used as gemstones
a hard, glassy mineral composed of magnesium-aluminium oxide found in metamorphosed limestones and many basic and ultrabasic igneous rocks. Formula: MgAl2O4
spinel also spinelle
A hard, variously colored cubic mineral, having usually octahedral crystals and occurring in igneous and metamorphosed carbonate rocks. The red variety is valued as a gem and is sometimes confused with the ruby. Chemical formula: MgAl2O4.
Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum.
adjective 1. having no spines or quills. 2. having no spine or backbone. 3. having a weak spine; limp. 4. without moral force, resolution, or courage; feeble: a spineless, lily-livered coward. adjective 1. lacking a backbone; invertebrate 2. having no spiny processes: spineless stems 3. lacking strength of character, resolution, or courage
noun 1. ruby spinel.
- Spine of scapula
spine of scapula n. The prominent triangular ridge on the dorsal aspect of the scapula.
adjective 1. Botany. becoming spinelike. ending in a spine. bearing spines. 2. Zoology. somewhat spinelike; coarse, as hair. adjective (biology) 1. having or resembling a spine or spines 2. becoming spiny