from The American Heritage® Dictionary of the English Language, 4th Edition
- n.pl. Geology Irregular dark or light streaks in plutonic igneous rock that differ in composition from the principal mass.
- n.pl. Regions of a transparent medium, as of a flowing gas, that are visible because their densities are different from that of the bulk of the medium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Regions of a fluid having different refractive index because of their different density
- n. Irregular streaks of different composition in some igneous rocks
from The Century Dictionary and Cyclopedia
- In petrography, streaks or irregularly shaped portions of an igneous rock which differ in texture or composition from the main mass.
German, pl. of Schliere, from dialectal Shliere, streaks, from Middle High German slier, mud, slime, from Old High German sclierrun, pieces, bits.(American Heritage® Dictionary of the English Language, Fourth Edition)
German streaks (Wiktionary)