carbonado
Language: English
Part of speech: noun
Pronunciation: ipa: /ˌkɑːbəˈneɪdəʊ/
ipa: /-ˈnɑː-/
ipa: /ˌkɑɹbəˈneɪdoʊ/
Forms: form: carbonados
form: carbonadoes
Etymology: Borrowed from Portuguese carbonado (“carbonized”), probably from carbono (“carbon”) (currently only attested later than carbonado) + -ado (suffix forming adjectives from nouns meaning ‘something or someone who has suffered the action’). Carbono is borrowed from French carbone (“carbon”), from Latin carbō (“coal; charcoal”); for further derivation, see etymology 1.
Senses: examples: text: At present, equal attention is paid to irregular fragments of a blackish or greyish colour, occasionally of considerable size, also yielded by the washings of diamandiferous sand, which formerly passed unregarded. These fragments are now carefully colected, and have acquired some considerable value in commerce, where they are known under the name of carbonado or carbon. […] An examination of these numerous varieties has made it evident that between carbonado of a simply micro-crystalline texture, and the diamond regularly crystallised in diaphanous octahedrons, there exists an uninterrupted series of intermediate conditions.
ref: 1873 October, “Some New Facts Concerning the Diamond”, in William Crookes, editor, The Quarterly Journal of Science, and Annals of Mining, Metallurgy, Engineering, Industrial Arts, Manufactures, and Technology, volume III (New Series; volume X overall), London: Offices of the Quarterly Journal of Science, 3, Horse-shoe Court, Ludgate Hill; Paris: Friedrich Klincksieck; Leipzg: Alfons Dürr, →OCLC, page 439:
text: Brazil's carbonadoes are indispensable today for the speedy cutting of hard rubber, bakelite and fiber compounds. Their absolute precision is especially valuable in turning such instruments as high-power telescopes and microscope tubes.
ref: 1928 January, Orville H. Kneen, “Gems that Work for a Living: Black Diamonds, the Most Precious Stones on Earth, Put to Curious Industrial Uses”, in The Popular Science Monthly, volume 112, number 1, New York, N.Y.: Popular Science Publishing Company, →ISSN, →OCLC, page 133, column 1:
text: Carbonado, the granular variety of diamond, is a porous micro- or cryptocrystalline aggregate, composed of anhedral grains and crystallites of octahedral or, less commonly, cubic habit that range in size from 0.5 to 50 nm.
ref: 1974, Ye. V. Frantsesson, F. V. Kaminskiy, “Carbonado, a Diamond Variety of Nonkimberlitic Origin”, in Doklady: Earth Science Sections, Falls Church, Va.: American Geological Institute, →OCLC, page 117:
text: Carbonados are polycrystalline diamond aggregates of generally irregular shapes that have been observed in placer deposits and low-grade metamorphic rocks of mainly Brazil, Russia, South Africa, Ukraine, Venezuela, and the Central African Republic. […] Smith and Dawson (1985), consequently, suggested that carbonados could have been formed as a consequence of Precambrian impact events into carbon-bearing crustal rocks. All other traces of these impacts and the related impact structures apparently have been eroded, and only the carbonados had survived erosion and were then incorporated into sedimentary rocks.
ref: 2005, Wolf Uwe Reimold et al., “Economic Mineral Deposits in Impact Structures: A Review”, in Christian Koeberl, Herbert Henkel, editors, Impact Tectonics (Impact Studies), Berlin; Heidelberg: Springer-Verlag, →ISBN, →ISSN, section 3.2 (The Carbonado Conundrum), page 505:
topics: chemistry
geography
geology
mineralogy
natural-sciences
physical-sciences
synonyms: black diamond
glosses: A dark, non-transparent, impure form of polycrystalline diamond (also containing graphite and amorphous carbon) used in drilling.
Coordinate terms: ballas
boart
bort