ballasn.

Brit.

/ˈbaləs/, U.S.

/ˈbæləs/

Origin: A borrowing from Portuguese. Etymons: Portuguese balas, bala.

Etymology: < Portuguese balas, ballas (the specific sense with reference to diamonds is apparently not recorded in dictionaries of Portuguese, but is found in 20th-cent. use), specific use (although the form with medial -ll- is unexplained) of the plural of bala ball, bullet (see bale n.³), with reference to the round shape of the crystal aggregate.

A tough aggregate of minute, concentrically arranged diamond crystals, occurring naturally in rounded masses esp. in Brazil and South Africa, and mined or produced synthetically for industrial purposes. Cf. bort n.

ΚΠ

1931 Science 13 Feb. 185 Diamonds for industrial uses are classified into carbons (carbonado, black Brazilian diamonds), ballas, and boarts (borts)... Round white diamonds are often wrongly described as ballas, but these are merely boarts of round shape, which being easily cleaved, can in no wise be used in place of ballas.

1942 P. Grodzinski Diamond & Gem Stone Industr. Production App. I. 234 Ballas (also named Bort-Ballas), intermediate type between carbons and crystalline diamonds.

1961 Nature 7 Jan. 50/1 The rare ‘ballas’ form of natural diamond is referred to occasionally in the literature.

1989 Encycl. Brit. VI. 303/2 Ballas, or shot bort,..is extremely hard, tough, and difficult to cleave... Brazilian ballas is said to be the harder.

2004 Thin Solid Films 469–70 104/1 All annealed films resemble very much the natural and synthetic forms of polycrystalline diamond called ‘ballas’.

This is a new entry (OED Third Edition, June 2008; most recently modified version published online December 2021).

单词	ballas
释义	ballasn. Brit. /ˈbaləs/, U.S. /ˈbæləs/ Origin: A borrowing from Portuguese. Etymons: Portuguese balas, bala. Etymology: < Portuguese balas, ballas (the specific sense with reference to diamonds is apparently not recorded in dictionaries of Portuguese, but is found in 20th-cent. use), specific use (although the form with medial -ll- is unexplained) of the plural of bala ball, bullet (see bale n.³), with reference to the round shape of the crystal aggregate. A tough aggregate of minute, concentrically arranged diamond crystals, occurring naturally in rounded masses esp. in Brazil and South Africa, and mined or produced synthetically for industrial purposes. Cf. bort n. ΚΠ 1931 Science 13 Feb. 185 Diamonds for industrial uses are classified into carbons (carbonado, black Brazilian diamonds), ballas, and boarts (borts)... Round white diamonds are often wrongly described as ballas, but these are merely boarts of round shape, which being easily cleaved, can in no wise be used in place of ballas. 1942 P. Grodzinski Diamond & Gem Stone Industr. Production App. I. 234 Ballas (also named Bort-Ballas), intermediate type between carbons and crystalline diamonds. 1961 Nature 7 Jan. 50/1 The rare ‘ballas’ form of natural diamond is referred to occasionally in the literature. 1989 Encycl. Brit. VI. 303/2 Ballas, or shot bort,..is extremely hard, tough, and difficult to cleave... Brazilian ballas is said to be the harder. 2004 Thin Solid Films 469–70 104/1 All annealed films resemble very much the natural and synthetic forms of polycrystalline diamond called ‘ballas’. This is a new entry (OED Third Edition, June 2008; most recently modified version published online December 2021). < n.1931
随便看	monovalencies monovalency monovalent monovular monox heather monoxalate monoxenic monoxenous monoxide monoxides monoxy monoxy- monoxyle monoxylic monoxylon monoxylons monoxylous monozoan monozoic monozygosity monozygote monozygotic monozygous monradite monro