dark mineral

The deposits have the appearance of "flowers" in a darker mineral.

He looked as if he had just come off duty from construction mining, with his arms and face covered by stains of dark mineral dust.

Varieties deficient in hornblende and other dark minerals are called leucodiorite.

The shiny wet orange walls of meta-mprphic rock were striped black with darker minerals.

In geology, leucogranites are light colored granitic rocks with almost no dark minerals.

The pillar is fine grained alkalik igneous rocks, formed of dark minerals.

Biotite and/or hornblende constitute the dark minerals.

After a summer digging near the point where the sample had been found, he returned home in the autumn of 1577 with 200 tons of a dark mineral.

They are lighter in colour and lower in density than basalts or andesites, and contain fewer dark minerals.

Unlike granite, however, gneiss has wavy, irregular layers of light and dark minerals, such as quartz, feldspar, mica, and hornblende.

Medium grey andesite, an igneous volcanic rock, speckled with crystals of dark minerals, knobbed with hard protrusions.

He found a dark mineral which he named ytterbite and sent to Johan Gadolin at the University of Åbo for further analysis.

As general information, gneiss is a coarse-grained high grade metamorphic rock formed at high pressures and temperatures in which light and dark mineral constituents are segregated into visible bands.

The chemical reaction between the extreme heat and the comet's components transforms Troy into a sharp dark mineral crystal like creature, with the power to "extrude" other living being's life force and abilities.

The light minerals, consisting mostly of quartz and feldspar, are the hardest and most resistant, whereas the dark minerals, which are mostly biotite mica and hornblende, are softer and weather out faster.

Apart from quartz and the feldspars, most minerals are dark in colour, so basic rocks with no quartz tend to be dark-coloured, while acid rocks are much lighter and usually have only isolated specks of dark minerals.

Bedrock under the harbor and in the Harborview and Calf Pasture Beach area is interlayered Ordovician trap falls gneisses and Harrison Gneiss with dark minerals hornblende, biotite and garnet.

For these reasons they have been defined as a melanocrate series (rich in the dark minerals); and they are often accompanied by a complementary leucocrate series (rich in the white minerals feldspar and quartz) such as aplites, porphyries and felsites.

My mouth filled with the cold taste of lakewater instead, all those dark minerals, and suddenly the trees were shimmering before my eyes as if I were looking up at them through clear liquid, and the pressure on my chest had become dreadfully localized and taken the shapes of hands.