Lab quiz #2 rock identification

Breccia (sedimentary)

60% felsic > 40% matrix

Arkose sandstone (sedimentary)

40% quarts > 30% mafic

Quartz sandstone

100% quartz

Chert

<Quartz

Rock gypsum

<Gypsum

Shale

Clay, too fine to tell

Siltstone

Too fine to tell

Fossiliferous limestone

50% calcite shells, 50% other rock material

Coal

Looks exactly like shungite

Gabbro (igneous)

50% pyroxene, 50% plagioclase

Phorphyritic basalt (igneous)

30% Phenocryst (plagioclase), 70% ground mass

Pumice (igneous)

Very lightweight (floats), too fine to tell composition

Basalt (igneous)

Resembles black hematite, composition: too fine to tell

Vesicular basalt (igneous)

Porous, too fine to tell composition

Porphyritic andesite (igneous)

5% horn blend( black specs), 95% ground mass

Rhyolite (igneous)

Resembles chalk ( pinkish colour)

Granite (igneous)

QAP: alkali feldspar granite

Diorite (igneous)

“Salt and pepper”

QAP: Tonalite

slate (metamorphic)

Too fine to tell

Biotite shist (metamorphic)

Biotite ± quartz/ feldspar

Resembles a shiny mica

Phyllite (metamorphic)

Clay minerals-/+ quarts, feldspar

Gniess (metamorphic)

Quartz, feldspar, ± magnetite

Semi magnetic, of granite protolith

Gniess (metamorphic)

Quartz, feldspar, ± biotite

Granite protolith

Quartzite (metamorphic)

100% quarts, calcite look, quartz texture

Marble (metamorphic)

Calcite

(Same feel as calcite, pinkish colour like halite)

Muscovite- garnet shist (metamorphic)

Layers like mica

Greenstone (metamorphic)

Calcite ± magnetite

Spotted horn blend (metamorphic)

Biotite, quartz ± cordierite

Conglomerate ( sedimentary)

Larger minerals mixed with ground mass

Porphyritic granite (igneous)

Large phenocryst

Quartz, Kspar, plagioclase, biotite, hornblende