schlieren
/ˈʃlɪərən/plural noun
1- technical discernible layers in a transparent material that differ from the surrounding material in density or composition〈技〉纹影。
1.1
- Geology irregular streaks or masses in igneous rock that differ from the surrounding rock in texture or composition【地质】（火成岩的）异离体, 析离体。
词源
late 19th cent.: from German Schlieren, plural of Schliere 'streak'.