BY: Sidney Mufford
BIOTITE MICA
CALCITE
Chemical Formula: CaCO3 Cleavage: perfect on 3 directions with an angle of 74 degrees Colour: white, grey, yellow, green. Streak: White Hardness: 3 Lustre: Pearl like on cleavage surfaces Uses: used in some medication
FELDSPAR
Chemica formula: Al(Al,Si)3O8 Cleavage: Two or three palnes Lustre: Non-metallic Colour: pink, white, grey, and brown Streak: white Hardness: Harder than glass Uses: rubber, paint, plastic, tableware
FLOURITE
Chemical formula: CaF2 Cleavage: Octahedral Colour: white, purple, blue, green, red Lustre: vitreous Hardness: 4 Uses: toothpaste Streak: white
GALENA
Chemical formula: PbS Cleavage: bascal Colour: lead grey and silver Hardness: softer than fingernail Lustre: metaliic
GRAPHITE
Chemical formula: C Cleavage: Bascal Color: Iron black and steel grey Streak: grey and black Hardness: softer than fingernail Luster: metallic Uses: batteries and iron making
GYPSUM
Chemical formula: CaSO-2HO Cleavage: 1-2 planes Streak: white Hardness: softer than a fingernail Luster: translucent Colour: colourless Uses: drywall
HALITE
Chemical Formula: NaCl Cleavage: 3 directions cubic Colour: colourless or white, pink, red, yellow orange or grey Streak: white MOH’s scale: 2-2.5 Lustre: vitreous Other characterisics: Salty taste
HERMATITE
Chemical formula: Fe203 Cleavage: none Colour: dark grey and silver Streak: dark grey an silver Hardness: soft as finger nail Lustre: metallic Uses: jewelry
MAGNITITE
Chemical formula: Cleavage: Fe2Fe203 Colour: Black, grey, and brown Streak: black Hardness: harder than glass Lustre: metallic Uses: magnets and jewellery
MUSCOVITE MICA
Chemical formula: KAl2 Cleavage: 1 plane Colour: white, grey, silver Streak: white Hardness: 2-2.5 Lustre: pearly, silky
PYRITE
Chemical formula: Fes2 Cleavage: Indistinct Colour: pale brass-yellow Streak: greenish-balck Hardness: harder than glass Lustre: metallic Uses: mineral detectors in radio receivers
QUARTZ
Chemical formula: SiO2 Cleavage: Indistinct Colour: colourless Streak: White Hardness: harder than glass Lustre: non-metallic Uses: Jewelry
TALC
Chemical formula: Mg3Si4 Cleavage: one plane Colour: white, brown Streak: white Hardness: softer than fingernail Lustre: non-metallic Uses: paper making