hornblende
/ˈhɔːnblɛnd
/noun [mass noun]
A dark brown, black, or green mineral consisting of a silicate of calcium, magnesium, and iron, occurring in many igneous and metamorphic rocks.The main constituent phases of these rocks are plagioclase, hornblende, pyroxene, quartz and K-feldspar, and accessory phases include magnetite, sphene, zircon and apatite....
- Although each mound had substantial amounts of quartz and kaolinite, minerals that reflected differences in mound material included magnetite, gypsum, hornblende, hematite, goethite, and feldspars.
- All four samples are medium-grained, and comprise variable proportions of hornblende, feldspar and quartz with accessory biotite and titanite.
Origin
Late 18th century: from German, from Horn 'horn' + blende (see blende).