Practice identifying rocks and minerals for the science olympiad!
Quartz - crystal
Mineral Color: several possible, often white, clear, or pink Streak: colorless or light colored Layers: Texture: smooth Shiny: glassy luster in crystal form Hardness: Moh's scale 7 Other: hexagonal shape fracture (crystals) specific gravity: 2.65
Calcite - Iceland spar
Mineral Color: white/clear Streak: Layers: Texture: Shiny: Hardness: Other: reacts to acid rhomohedral crystals shows a double image
Mineral Color: copper red-orange (blue/green patina, like rust) Streak: copper red-orange Layers: Texture: Shiny: metallic luster Hardness: Other: bendable and conducts heat and electricity used to make wires when exposed to acid, it forms a blue-green patina. special forms: Float and denrytic
Mineral Color: gray Streak: gray Layers: breaks into cubes Texture: Shiny: metallic luster Hardness: Moh's scale 2.5 Other: high specific gravity (feels heavy for size) perfect cubic cleavage, most common lead ore Used in making crystal radios Exposure to acid causes a smell like rotten eggs!
Mineral Color: brassy yellow Streak: greenish-black Layers: Texture: Shiny: shiny metallic Hardness: Moh's scale 6 Other: Looks like gold, also called "fools' gold"
Mineral Color: White/pink Streak: colorless or white Layers: Texture: Shiny: glassy to pearly Hardness: Moh's scale 6 Other: Specific gravity 2.55 looks like marble most common mineral on earth harder than feldspar
(top black piece) Mineral Color: brown/black Streak: Layers: yes, flakes in thin sheets. It has perfect cleavage in one direction. Texture: smooth Shiny: glassy Hardness: Moh's scale 2.5-3, can be scratched by a fingernail Other: nonmetalic type of mica Can be used in insulation Color is caused by biologic materials exposed to oxygen as it cools.
Mineral AND a rock Color: white, red or blue Streak: white Layers: Texture: Shiny: glassy (vitreous) Hardness: Moh's scale 2.5 Other: salty, used for cooking and for road safety Perfect cubic cleavage forms when moisture evaporates
Intrusive Igneous Rock Color: varies, but often speckled gray, black, white or pink Streak: Layers: no Texture: big crystals Shiny: may have shiny flecks but has dull areas too Hardness: Other: often used for construction of buildings and monuments, polished for tile and countertops
(dark rocks) Extrusive Igneous Rock Color: black or dark Streak: Layers: Texture: little crystals Shiny: Hardness: Other:
Extrusive Igneous Rock Color: medium to dark Streak: Layers: Texture: full of different sizes of air bubbles Shiny: dull Hardness: Other: DOES NOT float in water AKA - "Lava rock" often used in landscaping similar to pumice, but cooled more slowly
Extrusive Igneous Rock Color: black Streak: none Layers: Texture: very smooth Shiny: glassy Hardness: Other: formed from lava, known as "nature's glass"
Sedimentary Rock Color: Streak: Layers: Texture: fine grained, sandpapery feel Shiny: dull Hardness: Other: feels like sand paper formed from sand
Sedimentary Rock Color: black, brown, gray Streak: black Layers: yes Texture: very fine particles, smooth, layered dirty feel Shiny: light sheen Hardness: Other: A common source of oil formed from silt
Conglomerate or pudding stone
Sedimentary Rock Color: Streak: Layers: Texture: coarse grained rounded pebbles, bumpy Shiny: dull Hardness: Other: formed in a moving river as it deposits pebbles, sand, and mud together, then all were compressed. Also known as pudding stone
Sedimentary Rock Color: always going to be grey (light or dark) Streak: Layers: Texture: fine particles powdery, often has fossils Shiny: dull Hardness: Other:made in coral reefs forms from shells and calcite Fizzes as it releases carbon dioxide when acid applied. Parent rock of marble
Mineral Color: purple, green to yellow or colorless Streak: Layers: Texture: smooth Shiny: glassy or pearly Hardness: Moh's scale 4 Other: makes massive crystals at times glows in ultraviolet light Used in the manufacturing process of steel You can tell purple fluorite from amethyst quartz by the shape of the crystals.
Mineral Color: steel gray Streak: Black Layers: Texture: greasy Shiny: dull metallic Hardness: Moh's scale 1 Other: made of pure carbon Uses: "lead" in pencils, sporting equipment like golf clubs, tennis racquets, and fishing poles
Gypsum - satin-spar
Mineral Color: white, gray, pearly Streak: Layers: Texture: fibers Shiny: satiny metallic luster Hardness: Moh's scale 2 Other: used to make insulation, plaster of paris and drywall
Mineral Color: steel gray, reddish brown Streak: red brown Layers: Texture: Shiny: metallic Hardness: varies on Moh's scale 1-6.5 Other: important ore of iron, used to make steel in its reddish form, the redness is caused by the rusting (oxidizing) of the iron inside
(light area) Mineral Color: white, sometimes colored by impurities Streak: Layers: Texture: rough, clay like Shiny: no Hardness: Moh's scale 2 Other:
Quartz - chert
Mineral Color: various, white to gray is common Streak: colorless or light colored Layers: Texture: smooth, chalky, waxy Shiny: Hardness: Moh's scale 7 specific gravity: 2.65 Other: part of the quartz family has been used in the past to make arrowheads
Mineral Color: white, green, or pink Streak: Layers: Texture: slick/soapy Shiny: pearly/waxy Hardness: Moh's scale 1 Specific gravity is 2.58 Other: Also known as soapstone
Sedimentary Rock Color: black or dark brown Streak: Layers: yes Texture: sooty Shiny: bright and dull bands Hardness: softer than anthracite coal Other: Contains very tiny fossils lower carbon content than anthracite coal
Metamorphic Rock Color: Streak: Layers:no Texture: coarse grains of minerals Shiny: Hardness: Other: sometimes has bands (stripes) of different colored minerals caused by the reorganization of minerals during metamorphosis
Metamorphic Rock Color: Comes in many colors Streak: Layers: Texture: Shiny: Hardness: Moh's scale 3 Other: Forms from limestone Contains minerals calcite and pyrite often carved by artists, relatively soft fizzes with dilute acid
Extrusive Igneous Rock Color: light gray Streak: Layers: Texture: full of small similar-sized air bubbles "frothy" Shiny: light sheen, not glossy Hardness: Other: used in soaps and polishes because of it's abrasive qualities floats in water,very light formed from lava that cools quickly, trapping air bubbles inside
Metamorphic Rock (formed from sandstone) Color: Streak: Layers: Texture: fine-grained Shiny: Hardness: Other:
Schist - garnet
Intrusive metamorphic rock (formed from magma, NOT lava, cools slowly) Color: dark red to brown Streak: colorless or light colored Layers: Texture: Shiny: glassy or dull Hardness: Moh's scale 6.5 Other: Can form garnet crystals
Metamorphic Rock Color: varies Streak: Layers: breaks in layers Texture: fine grained, minerals not visible Shiny: Hardness: Other: low-grade metamorphic rock, made up of mica
Metamorphic Rock Color: black Streak: Layers: breaks in layers Texture: fine grained, minerals not visible Shiny: high luster (shiny, semi-metallic)) Hardness: harder than bituminous coal Other: higher carbon content than bituminous coal
A natural combination of minerals.
What is "fracture"?
Fracture describes the shape or pattern of breakage that a rock or mineral shows when struck.
Desert Rose is a crystalline form of either gypsum or selenite. Both of these minerals are soft and can be scratched with your fingernail.
directions that a rock or mineral can be easily split. It is a tendency to split along a definite plane yielding a flat surface. Rocks or minerals perfect cleavage may split into layers, cubes or other crystals.
The way a mineral reflects light. Is it shiny, metallic or dull?
A geode is:
A volcanic rock with a hollow middle where crystals grow.
Mineral Color: white/clear Streak: Layers: Texture: Shiny: Hardness: Other: reacts to acid
A mineral is an inorganic, naturally occurring crystalline solid. It is made up of basic elements and compounds, like gold or sodium.
Extrusive igneous rock
Formed by the cooling of lava, outside the surface of the earth. Cools quickly.
Intrusive igneous rock
Formed by the cooling of magma, inside the surface of the earth. Cools slowly.
Rocks changed from sedimentary or igneous rock by intense heat and pressure from plate tectonics or other sources within the earth's crust.
Mineral Color: white Streak: colorless or light colored Layers: none Texture: smooth Shiny: Hardness: Moh's scale 7, Harder than glass, but softer than diamond or topaz Other: the milky color is caused by impurities like moisture when the crystals form.
Rank in order from least to greatest specific gravity: A. Kaolinite B. Copper C. Lepidolite D. Pyrite
A - Kaolinite C - Lepidolite D - Pyrite B - Copper
Mineral Color: iridescent, shades of blue and purple and brown Streak: grayish black Layers: Fracture is conchoidial (shell-like) Texture: smooth Shiny: Luster is metallic Hardness: Moh's scale 3 to 3.25, softer than a penny or glass Other: An important form of copper ore
Small particles of any type of rock (metamorphic, igneous, or sedimentary) broken off by erosion or weathering. Can be used to form new sedimentary rock.
Calcite - dogtooth crystal
Mineral Color: white/clear Other: A form of calcite that grows in the shape of dog's teeth, often in limestone caves near pools of water. reacts to acid rhomohedral crystals
Define "specific gravity"
The density of a mineral. Minerals with a high specific gravity will feel heavier than one of a low specific gravity for the same size piece.
How many chemical elements make up almost all (98%) of the earth's crust?
List the following in order from softest to hardest:
A. Quartz chert B. Bornite C. Talc D. Galena
C. Talc D. Galena B. Bornite A. Quartz chert
How are sedimentary rocks formed?
Layers of sediment are cemented together over time.
What is the state stone of Texas?
Who created the hardness scale used to classify rocks and minerals?
Which kind or kinds of energy and force drive the rock cycle?
Solar, radioactive, and gravity
What is physical weathering?
The breakdown of rocks without chemical change. Usually this is caused by abrasion.
What is chemical weathering?
Chemical reaction can break the bonds that hold rocks together causing them to crumble. Water is often a key ingredient to this, as well as warm weather.
What is biological weathering?
This is caused when plants or their roots push or pull rocks apart.
What causes erosion?
Wind, water, ice, and gravity can cause the movement of materials like soil, sand, silt, or sediment.
When rock cools more slowly, how does it affect the size of crystals that form in the rock?
The more slowly it cools, the larger the crystals will be.
What kinds of rock might have fossils?
Most are found in sedimentary rock, but some are in metamorphic rock too.
How are magma and lava different?
Magma is molten rock INSIDE the earth's surface. Lava is what we call it once it is above the surface.
What happens to water when it freezes?
It expands. This can get into cracks in rock and force the rock apart.
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