rhombohedron
/ˌrɒmbə(ʊ)ˈhiːdr(ə)n
/noun (plural rhombohedra /ˌrɒmbə(ʊ)ˈhiːdrə/ or rhombohedrons)
1A solid figure whose faces are six equal rhombuses.
1.1A rhombohedral crystal or other solid object.He arrived at this from a study of calcite crystals of various habits and noted that the cleavage rhombohedra were always the same....
- This Eagle mine is well known for dark spruce-green, rough-surfaced octahedra of fluorite associated with rhombohedra of rhodochrosite to 0.75 inch on edge.
- These are nearly always accompanied by parallel overgrowth of several flattened rhombohedra aligned along each scalenohedron's c-axis, forming ‘pagodas’.
Origin
Mid 19th century: from rhombus + -hedron, on the pattern of words such as polyhedron.