bonding, minerals and rocks

Question 1

what are crystals?

Answer 1

homogeneous solid formed by 3D pattern of atoms, ions and molecules. form most of solid earth.

Question 2

what are molecules?

Answer 2

group of 2 or more atoms of the same or different elements held together by chemical bonds. electrically neutral.

Question 3

what are minerals?

Answer 3

elements or chemical compounds that are normally crystalline and that has been formed as a result of geological processes.

Question 4

what does atmophile mean

Answer 4

volatile forms gases mainly in the atmosphere

Question 5

what does lithophile mean

Answer 5

silicates, oxides, rock forming. dominates crust and mantle

Question 6

what does chalcophile mean?

Answer 6

affinity for a sulfide liquid phase

Question 7

what does siderophile mean?

Answer 7

affinity for metallic liquid phase

Question 8

what is a mineral to a geologist?

Answer 8

homogenous naturally occurring solid substance with definable chemical composition and an internal structure of arranged atoms. they have a crystla lattice.

Question 9

what are polymorphs?

Answer 9

graphite and diamond have the same composition, but different crystal structures. this is a polymorph.

Question 10

how do we see inside crystals?

Answer 10

optical microscopy. x ray show individual atoms.

Question 11

how can you distinguish a mineral?

Answer 11

colour, streak, luster, hardness, specific gravity, crystal habit, fracture and cleavage.

Question 12

what is luster?

Answer 12

refers to the way the mineral surface scatters light

Question 13

why are silicate rocks important?

Answer 13

dominate crust in the mantle. mode of oxygen and solicon with other atoms. the ratio with these are important. 95% of the continental crust is made of silicate minerals.

Question 14

where do diamonds come from?

Answer 14

carbon travels to the mantle by subduction. diamonds can only form in the amntle around 150 km down, due to the extreme temperatures, pressure and conditions.caron containing rocks travel to the mantle when convergent plate boundaries collide, the diamond becomes trapped in the lithosphere mantle beneath continents. the magma rises when rifting occurs, bringing the diamonds with it, in something called kimberlite, and crushing kimberlite to get to it.

Question 15

why has the continental crust composed differently?

Answer 15

due to the size of the ions and the way elements are packed into mineral lattices.

Question 16

what did Bowen discover?

Answer 16

discovered that minerals solidify in specific series. continous and discontinous (minerals stop and start crystallising), tried to determie the sequence in which silicate mierals crystallise to form a melt.

Question 17

what is metamorphism?

Answer 17

new minerals that only grow under metamorphic conditions. it is the change of minerals in rocks, without melting into magma, occurring due to heat, pressure and chemically active fluids.

Question 18

what happens when you heat a rock?

Answer 18

happens at elevated temperatures. behave like soft plastics, can be squeezed or stretched. when you heat a rock, its ingredients transform into a new material. heat causes the atoms to vibrate and bend the chemical bonds.