Definition of conchoidal in English:


Pronunciation /käNGˈkoidl/ /kɑŋˈkɔɪdl/


  • Denoting a type of fracture in a solid (such as flint or quartz) that results in a smooth rounded surface resembling the shape of a scallop shell.

    ‘It occurs on conchoidal fracture surfaces developed in clay and tuffaceous sandstone on the Green Velvet claims, Inyo County, and as ‘specimens’ on the Wakefield property near Pozo, San Luis Obispo County.’
    • ‘Quartz-grain microtextures have received particular attention, and many distinctive textural features, such as conchoidal fractures and stepped surfaces, have been classified.’
    • ‘The conchoidal fracture exhibited by chert and obsidian allows them to be shaped into sharp points and edges.’
    • ‘The term flint is used here to describe high-purity microcrystalline quartz with a conchoidal fracture that is prominent in beds of Pennsylvanian age in the Appalachian region.’
    • ‘It has a conchoidal fracture and a calculated density of 3.51 gm / [cm.sup.3], just high enough to be recovered by the careful panner or through traditional placer techniques.’
    • ‘The mineral is brittle, has conchoidal fracture, and may have poor cleavage parallel to b { 010 } and parting parallel to c { 001 }.’
    • ‘Its fracture is conchoidal to uneven, its density is about 3.73, and its hardness varies from 5.5 to 6.5.’
    • ‘It commonly occurs as anhedral crystals, some displaying conchoidal fracture, and is usually about 1-3 mm in size.’
    • ‘It has a distinct, almost perfect cleavage on { 1011 } and an uneven to imperfectly conchoidal fracture.’
    • ‘They are quite brittle and break with a conchoidal fracture.’
    • ‘Further, the anterior portion of the right fracture, where it is similar to that of the left fracture, exhibits conchoidal fracture of the dorsal carapace material which is preserved as a black, possibly manganiferous, substance.’
    • ‘The mineral is brittle with a conchoidal to uneven fracture.’