Lab 5 // Metamorphic Rocks

Question 1

Slate

Answer 1

Texture: foliated, fine grained, slaty cleavage
Properties: grains too small see
Parent Rock: mudstone or shale
Uses: roofing slate, table tops, floor tile, blackboards

Question 2

Gneiss

Answer 2

Texture: foliated, medium or coarse grained, gneissic banding
Properties:
-light minerals (mainly quartz)
-dark minerals (mainly biotite)
Parent Rock: mudstone, shale, slate, phyllite, schist, granite, diorite
Uses: construction stone, decorative stone, sources of gemstones

Question 3

Quartzite

Answer 3

Texture: nonfoliated, medium or coarse grained crystalline or sandy texture
Properties: quartz, hard (scratches glass and a streak plate)
Parent Rock: sandstone
Uses: construction stone, decorative stone

Question 4

Marble

Answer 4

Texture: nonfoliated, medium or coarse grained crystalline texture
Properties: these samples = calcite (marble can also be made of dolomite if the parent rocks was dolostone), soft (doesn’t scratch glass)
Parent Rock: limestone (for a marble with a calcite composition, it would be dolostone if the marble was made of dolomite)
Uses: art carvings (soft), construction stone, decorative stone, source of lime for agriculture (dolomitic marble)

Question 5

Schist (muscovite garnet schist)

Answer 5

Texture: foliated, medium or coarse grained schistosity (could also add porphyroblastic)
Properties: lots of mica (mainly muscovite in these samples), garnet (these rocks show a lot of ‘bling’
Parent Rock: mudstone, shale, slate, phyllite
Uses: construction stone, decorative stone, sources of gemstones

Question 6

Soapstone

Answer 6

Texture: nonfoliated, (may show a bit of a foliation), either fine or medium grained, microcrystalline (fine), or crystalline (medium)
Properties: talc, very soft (can be scratched with your fingernail), soapy feel
Parent Rock: basalt, gabbro, or ultramafic igneous rocks (eg. peridotite)
Uses: art carvings (soft), construction stone, electrical insulators, talcum powder

Question 7

Phyllite

Answer 7

Texture: foliated, fine grained, phyllite textures
Properties: glassy metallic shine due to abundant aligned fine grains of mica (muscovite mainly)
Parent Rock: mudstone, shale, slate
Uses: construction stone, decorative stone, sources of gemstones