Unit 6 + 7 Flashcards
Definition of a mineral
Naturally occurring combination of specific elements which are arranged in a particular repeating 3-D structure
What is a rock?
Naturally occurring aggregates (mixture) of minerals
What is silicate minerals?
These are minerals made out of oxygen and silicon. It’s majority of the earths crystal elements.
What are carbonate minerals?
Made out of carbonate ions. There are most common as the mineral calcite marine animals also construct their shells from calcite.
How does cooling rate affect growth?
Fast cooling equals small minerals slow cooling equals large minerals
What is mineral precipitation?
Precipitation from an aqueous solution result in the formation of mineral crystals
What is metamorphism?
The alternation of the composition or structure of a rock or mineral by heat and pressure it forms, new minerals from elements existing in old minerals
What is organic formation?
Minerals formed from biological activity, shells, teeth, and bones
Mineral streak
The colour of the mineral when it’s powdered a better diagnostic than colour
Opacity
The ability to transmit light specifically in this situation through minerals
What is luster?
Describes the quality of light reflected from the surface of a mineral
What is Crystal habit?
The natural shape of individual crystals it depends on crystal structure and growth conditions
What is mineral cleavage?
The tendency for minerals to split along definite plan it’s controlled by the presence of planes and weakness with the crystal structure
What is a mineral fracture?
How minerals break when there are no planes of weakness
What are the two main types of fractures?
Irregular fracture, which is uneven breaking, the surface will have lumps and crevices. And conchoidal fracturing which is circular or semicircular ridges and furrows so more of a smooth texture.
What is exosolution?
This is the process, through which an initially homogeneous solid solution, separates into at least two different crystalline minerals, without the addition or removal of any minerals
What is the rock cycle driven by?
Earths, internal heat, engine, and the hydrological cycle
What is magma?
Molten or semi molten rock under the Earth surface, it takes a very long time to form, and it is an intrusive igneous rock (comes from plutons)
What is lava?
Molten or semi molten rock above our surface and it can cool really quickly and it also forms extrusive igneous rocks (comes from volcanoes)
What is partial melting?
When only a portion of solid material is melted, minerals melted different temperatures, so it may not melt at the same time
What are the two ways to form magma or melt rock?
Decompression melting, which is when the body of rock remains at the same temperature, but the pressure is reduced (it’s moving towards earth surface) and flux melting, which is when a body of rock close to its melting point has an injection of water, which reduces the melting temperature
How does magma move towards the surface?
Because it is less dense than the surrounding rock, it will slowly creep up, as well as it breaks and melts the surrounding rock
What is a pluton?
A body of solid rock formed by the complete cooling or crystallization of a magma body below earth surface
What is phaneritic texture
Igneous rocks, with a large visible crystals
What is pegmatitic texture?
Igneous rocks, with exceptionally large, visible mineral crystals
What is aphanitic texture?
Igneous rocks, with small mineral crystals, creating fine grains texture
What is a glassy texture
Igneous rocks, with no mineral crystals, creating a glass like texture
What is tephra?
Rock fragments, dust, and gas produced during explosive volcanic eruptions. It’s also called pyroclastic rock.
What is porphyritic texture?
This is igneous rocks with both large and small crystals
What does the amount of silica and magma dictate?
How far down the reaction of magma can go so all reactions will stop once all the silicone is used up
What is felsic magma?
This is silica rich so over 65%. This is formed by partial melting of the continental crust. It’s very thick magma at a low temperature and it’s dominated by light coloured minerals.
What is intermediate magma?
This is 52 to 65% silica it’s formed by the partial melting of the continental crust. This magma chamber will pass through the continental crust, and it contains dark and light minerals.