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/streek/, n.1. a long, narrow mark, smear, band of color, or the like: streaks of mud.2. a portion or layer of something, distinguished by color or nature from the rest; a vein or stratum: streaks of fat in meat.3. a vein, strain, or admixture of anything: a streak of humor.4. Informal.a. a spell or run: a streak of good luck.b. an uninterrupted series: The team had a losing streak of ten games.5. a flash leaving a visible line or aftereffect, as of lightning; bolt.6. Mineral. the line of powder obtained by scratching a mineral or rubbing it upon a hard, rough white surface, often differing in color from the mineral in the mass, and serving as an important distinguishing character.7. Plant Pathol.a. an elongated, narrow, superficial lesion on stems or leaf veins, becoming brown and necrotic.b. any disease characterized by such lesions.v.t.9. to mark with a streak or streaks; form streaks on: sunlight streaking the water with gold; frost streaking the windows.10. to lighten or color (strands of hair) for contrastive effect.11. to dispose, arrange, smear, spread, etc., in the form of a streak or streaks: to streak cold germs on a slide for microscopic study.v.i.12. to become streaked.13. to run, go, or work rapidly.14. to flash, as lightning.15. to make a sudden dash in public while naked, esp. as a prank.[bef. 1000; (n.) ME streke, akin to strike, OE strica stroke, line, mark; c. G Strich, Goth striks stroke, L strigil STRIGIL; (v.) late ME streken to cross out, deriv. of the n. (akin to STRIKE, STROKE1)]Syn. 3. cast, touch, element, trace.
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Colour of a mineral in its powdered form, usually obtained by rubbing the mineral on a hard, white surface (e.g., a tile of unglazed porcelain) to yield a streak of fine powder.The streak's colour is usually constant for a given mineral, even if the mineral varies in colour as it occurs in the field or if the streak is different from the colour of the unpowdered mineral. Streak is diagnostically useful because it may distinguish between mineral species that are otherwise similar in appearance.* * *
▪ mineral colourthe colour of a mineral in its powdered form. It is usually obtained by rubbing the mineral on a hard, white surface, such as a tile of unglazed porcelain, so as to yield a line, or streak, of fine powder. The colour of the streak is usually constant for a given species of mineral, even though the mineral may vary considerably in colour as it occurs in the field. Indeed, the colour of a streak may differ considerably from the colour of the unpowdered mineral. Streak is one of the more useful diagnostic properties, since it is a quick way to distinguish between different species of minerals that are otherwise similar in appearance.* * *
Universalium. 2010.
