schlieren

[ shleer-uhn ]

noun

, (used with a plural verb)

1. Petrography. streaks or irregularly shaped masses in an igneous rock that differ in texture or composition from the main mass.
2. Physics. the visible streaks in a turbulent, transparent fluid, each streak being a region that has a density and index of refraction differing from that of the greater part of the fluid.

schlieren

/ ˈʃlɪərən /

noun

1. physics visible streaks produced in a transparent medium as a result of variations in the medium's density leading to variations in refractive index. They can be recorded by flash photography ( schlieren photography )
2. streaks or platelike masses of mineral in a rock mass, that differ in texture or composition from the main mass

schlieren

/ shlîr′ən /

1. Irregular dark or light streaks in plutonic igneous rock. Schlieren have the same general mineral composition as the rocks in which they are found, but they are usually slightly darker or lighter than the rest of the rock because of differences in the ratios of the mineral types they include. They are typically a few centimeters to tens of meters long and can form in various ways, including by sorting of minerals during magma flow and through the gravitational settling of minerals during magma cooling and solidification.
2. Regions of a transparent medium, as of a flowing gas, that are visible as light or dark areas because their densities are different from that of the bulk of the medium.

Derived Forms

• ˈschlieric, adjective

Word History and Origins

Origin of schlieren¹

1885–90; < German, plural of Schliere streak

Word History and Origins

Origin of schlieren¹

German, plural of Schliere streak

Example Sentences

After correctly spelling back-to-back German-derived words — Kneippism and schlieren — he was knocked out by diallage, a dark green or bronze-colored laminated pyroxene common in certain igneous rocks.

From Washington Post

Parallel, streaming lines were visible on its surface—Schlieren lines, formed by two types of molten glass swirling together as the blobs arced through the atmosphere.

From The New Yorker

Parallel, streaming lines were visible on its surface—Schlieren lines, formed by two types of molten glass swirling together as the blobs arced through the atmosphere.

From The New Yorker

We gratefully acknowledge M. M. Wilhelmus for the original development of laboratory controlled migrations and for advice on development of the current facility; E. Meiburg for technical advice; and R. Strickler for assistance in development of the schlieren imaging system and use of his facilities for obtaining Fig. 4a.

From Nature

A Schlieren photograph — which shows density changes in fluids — of ripples in mercury.

From Nature