Definition of euhedral in English:

euhedral

adjective

Geology
  • (of a mineral crystal in a rock) bounded by faces corresponding to its regular crystal form, not constrained by adjacent minerals.

    • ‘The remaining 5-10% of zircon grains are rhombic, prismatic or long-prismatic euhedral crystals, and are always transparent and colourless to pale pink.’
    • ‘Some biotite crystals form perfectly euhedral plates, others show a reaction rim rich in opaque granules towards the surrounding microfelsitic base.’
    • ‘The mineral separates provided a population of euhedral, prismatic crystals, which are either transparent and colourless or chocolate brown and translucent to opaque.’
    • ‘Titanite occurs as up to 2 cm long, dark brown, euhedral crystals in textural equilibrium with the other minerals.’
    • ‘During crystallization of the derivative granite, minor secondary zircon grew around the older cores, resulting in euhedral crystal forms of all the grains.’

Pronunciation:

euhedral

/juːˈhiːdr(ə)l/