Term
|
Definition
| Nonmetallic, Hardness 5.5-6, Streaks white to pale grey, Color: dark green to gray; Forms short, 8-sided prisms; two good cleavages that intersect at 87 degrees and 93 degrees (nearly right angels) SG= 3.2-3.4. Some uses: Pyroxene mined as an ore of lithium, for making steel. |
|
|
Term
|
Definition
| Nonmetallic, Hardness 9, Streaks white or not at all-may scratch the streak plate. Color: Gray, white, black or colored (red, blue, brown, yellow), Hexagonal prisms with flat striated ends, Opaque to Transparent, Cleavage absent; SG: 3.9-4.1 H9 Some Uses: Used for abrasive powders to polish lenses; gemstones (Red Ruby, Blue Saphire); Emery cloth. |
|
|
Term
|
Definition
| Maybe Metallic or Non-Metallic. Class sample was non-metallic. Hardness 1-5.5. Streaks yellow-brown. Color: yellow brown to dark brown; tarnishes yellow to brown. Amorphous masses; Luster is dull or earthy. Hard or Soft, SG = 3.3-4.3. Some Uses: Yellow Pigment. Ore of Iron for steel tools, nails and bolts, bridges. |
|
|
Term
|
Definition
| Metallic. Hardness 1 (very soft and could rub off onto your fingers), Streaks: Dark Grey (like pencil lead), Color: Dark silvery grey to black; forms flakes, short hexagonal prisms, and earthy masses, greasy feeling, very soft, Cleavage:Excellent in 1 direction; SG= 2.0-2.3. Some Uses: Used as a lubricant (as in graphite oil), pencil leads, fishing rods. |
|
|
Term
Plagioclase Feldspar
[image] |
|
Definition
| Non-Metallic. Hardness: 6. Streaks: White. Colorless, white, gray, or black; may have iridescent play of color from within; Translucent; Forms striated tabular crystals or blades; Cleavage: Good in two directions at nearly 90 degrees, SG= 2.6- 2.8. Some Uses: Used to make ceramics, glass, enamel, soap, false teeth, scouring powders. |
|
|
Term
Biotite Mica--- Black Mica
[image] |
|
Definition
| Nonmetallic. Hardness 2.5-3. Streak: Gray-Brown. Color: Black, green-black, or brown-black; Cleavage excellent. Forms short prisms that split easily into very thin flexiable sheets. SG= 2.7-3.1. Some uses: Used for fire-resistant tiles, rubber, paint. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 3.5-4. Streak: White. Color: White, gray, creme or pink, usually opaque. Cleavage: excellent in 3 directions; Breaks into rhombohedrons. Resembles calcite, but will effervesce in dilute HCI only if powdered. SG=2.8-2.9. Some Uses: Ore of magnesium metal; soft abrasive; used to make paper. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 2. Streak: White. Colorless, white, or gray. Forms tublar crystals, prisms, blades, or needles (satin spar variety); Transparent to translucent. VERY Soft. Cleavage: good. SG= 2.3 Some Uses: Plaster-of-paris, wallboard, drywall, are sculpture medium (alabaster). |
|
|
Term
|
Definition
| Metallic. Hardness: 6-6.5. Streak: Dark Grey. Color: Silvery gray to black. Opaque; forms octahedrons; tarnishes gray. No Cleavage. Attracked to a magnet (the strongest of all minerals!) and can be magnetized. SG=5.0-5.2. Some Uses: Ore of Iron for Steel, brass, bronze, tools, vehicles, nails, and bolts, briges, etc. |
|
|
Term
Pyrite--- Fools Gold
[image] |
|
Definition
| Metallic. Hardness: 6-6.5. Streak: Dark gray. Color: silvery gold; tarnishes brown; Cleavage absent to poor. Brittle; Forms opaque masses, cubes (often striated) or pyritohedrons. SG= 4.9-5.2 Some Uses: Ore of sulfur, for sulfuric acid, explosives, fertilizers, pulp processing, insecticides. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 3. Streak: White. Usually colorless, white, or yellow, but maybe green, brown, or pink; Opaque or transparent; Excellent Cleavage in 3 directions NOT at 90°; Forms prisms, rhomnohedrons, or scalenohedrons that break into rhomnohedrons; Effervesces in dilute HCI; SG=2.7. Some Uses: Used to make antacid tablets, fertilizer, cement; Ore of calcium. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 4. Streak: White. Colorless, purple, blue, gray, green, or yellow. Cleavage excellent; Crystals usually cubes; Transparent or opaque. Brittle! Our sample, when scraped with our fingernail, came apart like sand. Small white-clear crystals with jade colored cubes. SG= 3.0-3.3. Some Uses: Source of fluorine for processing aluminum, flux in steel making. |
|
|
Term
|
Definition
| Metallic or Nonmetallic. Hardness: 1-6. Streak: Red to Red-Brown. Color silvery gray, reddish silver, black, or brick red; Tarnishes red; Opaque; Soft (earthy) and hard (metallic) varieties have same streak. Forms thin tabular crystals or massive; May be attracked to a magnet. SG= 4.9-5.3. Some Uses: Rouge makeup and polish; red pigment in paints, Ore of iron for steel tools, vehicles, nails and bolts, bridges, etc. |
|
|
Term
Muscovite Mica--White Mica
[image] |
|
Definition
| Nonmetallic. Hardness: 2-2.5. Streak: White to none. Color: Colorless, yellow, brown, or red-brown. Forms short opaque prisms; Cleavage excellent in 1 direction. can be split into thin flexiable transparent sheets. SG=2.7-3.0. Some Uses: Computer chip substrates, electrical insulation, roof shingles, facial makeup. |
|
|
Term
|
Definition
Nonmetallic. Hardness:7. Streak: White (will not actually color on the streak plate but will scratch it). Usually colorless, white, or gray but uncommon varieties occur in all colors; Transparent to translucent; Luster greasy; No cleavage; Forms hexagonal prism and pyramids; SG= 2.6-2.7. Some Uses: Used as an abrasive, used to make glass, gemstones.
Some quartz varieties are:
var. flint (opaque black or dark gray)
var. smoky (transparent gray)
var. citrine (transparent yellow-brown)
var. amethyst (purple)
var. chert (opaque gray)
var. milky (white) |
|
|
Term
|
Definition
| Metallic. Hardness:3.5-4. Streak: Dark gray. Color: Bright silvery gold; tarnishes bronze brown, brassy gold, or iridescent blue-green and red. Brittle. No cleavage. Forms dense masses or elongate tetrahedrons. SG=4.1-4.3. Some uses: Ore of copper for pipes, electrical circuits, coins, ammunition, brass, bronze. |
|
|
Term
|
Definition
| Metallic. Hardness: 2.5. Streak: Gray to dark gray. Color: Bright silvery gray; tarnishes dull gray; Forms cubes and octahedrons; Brittle; Cleavage good in three directions, so breaks into cubes. SG= 7.4-7.6. Some Uses: Ore of lead for TV glasses, auto batteries, solder, ammunition, paint. |
|
|
Term
|
Definition
| Nonmetallic. Harness:5.5. Streak: White to pale gray. Color: Dark gray to black; Forms prisms with good cleavage at 56º and 124º, Brittle; Splintery or asbestos forms. (My opinion is it looks like a cross between coal and mini layers of shale). SG=3.0-3.3. Some Uses: Fibrous varieties used for fire-resistant clothing, tiles, brake linings. |
|
|
Term
|
Definition
| Nonmetallic. Hardness:7. Streak: White* may not leave any color but will scratch the plate. Color: pale or dark olive-green to yellow, or brown; Forms short crystals that may resemble sand grains (will scrape off with your finger nail like sand), Conchoidal fracture; Cleavage absent; Brittle. SG=3.3-3.4. Some Uses: Gemstone (peridot), Ore of magnesium metal. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 1. Streak: White. Color: White, gray, pale green (as my sample was) or brown, Forms cryptocrystalline masses that show no cleavage; Luster is silky to greasy; Feels greasy or soapy (talcum powder); very soft. SG= 2.7-2.8. Some Uses: Used for talcum powder, facial makeup, ceramics, paint, sculptures. |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 2-2.5. Streak: White. Color: Dark green. Cleavage excellent; Forms short prisms that split easily into thin flexiable sheets. (Google image show a hard rock that is silvery, glittery gray colored) Luster bright or dull. SG= 2-3. Some Uses: Used for fire-resistant tiles, rubber, paint, art sculpture medium. |
|
|
Term
|
Definition
Nonmetallic. Hardness: 7. Streak: White* (will not color the streak plate but will scratch it). Color: Usually red, black, or brown, sometimes yellow, green, pink. Forms dodrcahedrons. Cleavage absent but may have parting. Brittle; Transulcent to opaque. SG= 3.5-4.3. Some Uses: Used as abrasive; gemstone.
(Our sample set had three stones very similar to the ones above. Dull or glassy appearing.) |
|
|
Term
|
Definition
Nonmetallic. Harness: 1-2. Streak: White. Color: White to very light brown; commonly forms earthy. Microcrystalline masses. Cleavage excellent, but absent in hand samples. SG= 2.6. Some Uses: Used for pottery, clays, polishing compounds, pencil leads, paper.
(Looks like a very hard piece of chalk) |
|
|
Term
Potassium Feldspar
[image][image] |
|
Definition
Nonmetallic. Hardness: 6. Streak: White. Color: Orange, brown, white, green, or pink. Forms translucent prisms with subparallel exsolution lamellae; Cleavage excellent in two directions at nearly 90º. SG= 2.5-2.6. Some Uses: Used to make ceramics, glass, enamel, soap, false teeth, scouring powders.
(Exam sample will be pink, lab tray sample was greenish white.) |
|
|
Term
|
Definition
| Nonmetallic. Hardness: 2.5. Streak: White. Color: Colorless, white, yellow, blue, brown, or red. Transparent to translucent; Brittle. Forms cubes. Cleavage excellent in 3 directions, so breaks into cubes. Salty tates. SG= 2.1-2.6. Some Uses: Table salt, road salt, used in water softners, and as a preservative. Sodium Ore. |
|
|
Term
Specular Hematite
[image] |
|
Definition
Metallic. Hardness: 5-6. Streak: Deep Red. Color: Steel Gray. Glittery and can rub off onto your hands as glitter. No cleavage. Identification in hand sample:
Shining gray metallic lustre and deep-red streak are indicative.
Associations:
Produced by weathering and hydrothermal alteration of iron-bearing minerals.
Industrial / ecomonic uses:
Important ore of iron. |
|
|
