IPA: /həʊləʊˈhiːdrəl/
KK: /həˈloʊhɪdrəl/
This word describes a type of crystal that has all the necessary flat surfaces to show complete symmetry in its structure.
The mineral was classified as holohedral due to its perfectly symmetrical crystal faces.
Holohedral → It is formed from "holo-" (from Greek "holos", meaning whole or entire) and "hedron" (from Greek "hedra", meaning face or base). The word describes a solid that has all of its faces present, hence being whole or complete in its surface structure.
Think of 'whole' ('holo-') to remember that 'holohedral' refers to a solid with all its faces present.