Lecture 2 Flashcards
Mineral ?
Natural occuring,
inorganic,
solid,
ordered internal molecular structure,
definite chemical composition
Rock ?
Solid mass of minerals
Mineral structure ?
Consists of an ordered array of atoms chemically bonded to form a particular crystalline structure
Polymorph ?
Elements can join in more than one geometric arrangement, chemical composition stays the smae, physical propoerties differ (Ex. Diamond and graphite)
Crystal habit (shape) ?
External expression of orderly internal arrangement of atoms.
Lustre ?
Apparence of mineral in reflected light,
Metallic and Non-Metallic
Colour ?
Obvious but not a diagnostic tool,
Slight impurties can produce strong colour variations
Streak ?
Colour of mineral in its powdered form
Hardness ?
Resistance of mineral to abrasion or scratching,
Minerals compared on Mohs scale
Cleavage ?
Tendancy to break along planes of weak bonding,
Produces flat, shiny surfaces
Fracture ?
Absence of cleavage when a mineral is broken ?
Specific gravity ?
Ratio of weight of a mineral to the weight of an equal volume
Class the most abundant mineral in Earth’s (OSAICSPM)
Oxygen, Silicon, Alluminium, Iron, Calcium, Sodium, Potassium, Magnesium
The Silicates ?
Most common mineral group,
Basic building block : silicon-oxygen tetrahedron
Complex silicate structrures
Single chains, Double chains, Sheet structures, 3D framework
What are the ferromagnesian (dark) silicates ? (IiIm)
Minerals containing ions of iron or magnesium
Most common ferromagnesian (dark) silicates ? (OPABG)
Olivine, Pyroxenes, Amphiboles, Biotite, Garnet
What are the nonferromagnesian (light) silicates ? (APCS)
Minerals containing various amounts of aluminium, potassium, calcium and sodium
Most common nonferromagnesian (light) silicates ? (MFQC)
Muscovite, Feldspar, Quartz, Clay
Important non-silicate minerals ? (OHSSneHCP) (in …ides)
Oxides, hydroxides, sulphides, sulphates, native elements, halides, carbonates, phosphates.
