minerals and rocks Flashcards
reflect light off its surface (pearly, dull, shiny, etc.)
luster
opaque, translucent, transparent
ability to transfer light
color of the mineral in powdered form
streak
octahedron, dodecahedron, cubes
crystal shape
minerals toughness or resistance to breaking or deforming. Brittle, malleable, elastic, thin shavings
tenacity
resistance of the mineral to abrasion or scratching
Hardness
break along the planes of weak bonding
cleavage
irregular when a mineral breaks and exhibits an uneven surface. Conchoidal when It breaks into smooth curves surfaces, splintery, fibrous
fractures
ratio of density of the mineral to the density of the water
specific gravity
what are the special properties of minerals?
- Taste
- Odor
- Attraction to magnets
- Fluorescence
- Radioactivity
- Reactivity
why is color not a reliable properly
color may be changed due to impurities
rock-forming minerals, also. Called economic minerals
minerals
explain silicates
- Oxygen and silicon
- Most abundant in the earth’s crust
- 96% of the earth’s minerals
what are the mineral groups of silicates
- Feldspar, quartz, mica, amphibole, pyroxene, and olivine.
explain non-silicates
- Less abundant in the earth’s crust
- Economic importance
- Oxides, carbonates, sulfates, halides
- Main components of sedimentary rocks
how are non-silicates economically important
- Calcite, cement
- Iron and aluminum for automobiles and etc
- Oxides like hematite and magnetite, ores of iron
how are gemstones identified
- Precious or semiprecious
- Not by mineral content but by color
- Naturally occurring solid aggregates of one or more minerals
Rocks
how are rocks identified
mineral and texture
how are they classified
igneous, sedimentary, and metamorphic rocks
are the changed chemical or physical?
both
explain the rock cycle
Melting of the rocks occurs in the upper mantle and earth’s curst because of extreme heat. Molten Rocks AKA magma rise to the surface because they are less dense than the surrounding rocks. The Lava cools and solidifies through a process known as crystallization or solidification. Can either solidify on the surface or below it. These become igneous rocks.
Through uplifting, the igneous rocks are exposed to the surface. Due to the atmosphere, they undergo weathering. The rocks become loose soil due to the agents of erosion such as running water, wind, waves, and glaciers, or the action of gravity. These particles dissolve and become sediments. The sediments are deposited to the sea, rivers, or any other bodies of water. They undergo lithification and are transformed to sedimentary rocks. Sedimentary rocks are formed by the compaction due to the weight of the overlying rocks or are cemented by the water that fills the spaces between the particles.
Sedimentary rocks may be buried and subjected to great pressure and intense heat.. Due to the changes in temperature, they undergo a physical and chemical change and transform to metamorphic rocks. If metamorphic rocks are exposed to extreme heat and pressure down the earth’s mantle, they melt and form magma, which repeats the cycle.
Formed by fire since they originate from the magma produced by the melting of rocks in the hot mantle.
Igneous
how does an igneous rock form?
when it cools and crystallizes
what do you call when it solidifies at the surface
extrusive
explain extrusive rocks
Tiny crystals are formed as a result of the rapid cooling of magma on the surface.
what do you call when it solidifies under the surface
intrusive
explain intrusive
- Large crystals that can be seen by the unaided eye.
- Result from the cooling of magma beneath the earth’s surface
igneous Mainly compose of _____ minerals
silicate
most abundant component of igneous rocks
oxygen and silicon (aluminum, calcium, sodium, potassium, magnesium, and iron)
Compacted and cemented sediments
sedimentary rocks
what are the 2 different sources of sedimentary rocks
weathered rocks that produce particles AKA detritus. (Detrital sedimentary rock) and soluble material produced by chemical weathering. Chemical sediments forms chemical sedimentary rocks
how do sedimentary rocks play an Important role in the study of history on earth
Fossils or remains of prehistoric plants or animals are embedded in sedimentary rocks.
transformation or change in form.
Metamorphic rocks
do metamorphic rocks have parents
yes
- _____________________________ cause the metamorphism of rocks.
Heat, pressure, and chemically active fluids
- Heat causes a _____________ of minerals present in rocks, so new minerals are formed.
recrystallisation
