The dictionary says that a mineral is: “a naturally occurring … solid substance having a definite chemical composition and characteristic crystalline structure, color, and hardness.” [American Heritage Dictionary] This means that minerals are formed by nature and are solid. They are made up of chemicals that form crystals. They are identified by the characteristics that are in all pieces of the same mineral, no matter where it's found. Some minerals have just one mineral in them, like gold.
Use these links to read the texts about minerals:
Common minerals and metals: uses and importance
The Earth - nature's storehouse
People and Earth's minerals
Dynamic Earth
Task
Here you should publish the information about the rocks, minerals or gemstones that are mined with surface mining. You should describe the mineral characteristics and your experimental data.
For example:
Alexandrite
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Mineral characteristics
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Mineralogists views
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Your conclusions
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Chemical Symbol
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BeAl2O4
| It has aluminum, beryllium, and oxygen in it. |
Color
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Green or red
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In sunlight/fluorescent light the stone is green.
In regular light bulb light or candlelight, the stone is red. |
Streak
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White
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When the stone is rubbed on a white plate, it leaves a white dust. If the stone is crushed, this is what color the powder would be.
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Transparency
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Transparent to translucent
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You can see through some stones and others are blurry to look through.
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Luster
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Glassy
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It shines like glass.
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Cleavage
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Imperfect
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If you break this mineral, it will not split smoothly and evenly. You can’t break it over and over again and get the same shaped pieces.
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Fracture
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Conchoidal
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The stone has a smooth, shell-like surface when it is broken.
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Magnetism
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None
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It will not attract or be attracted to a magnet.
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Hardness
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8.5
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The stone is hard. It will scratch the streak plate that you test it on. It would also scratch a nail!
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Specific gravity
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3.5
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If you held it, this stone would seem a little bit heavier than its size would make you think it would be.
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Crystal shape
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Orthorhombic
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Кристаллы корунда в полевом шпате.
ReplyDeleteСингония тригональная
Твердость
9
Удельный вес
3,95-4,1
Спайность
Псевдо спайность по двойникованию
Излом
раковистый
Цвет
черный
Цвет в порошке
белый
Блеск алмазный
Crystal system trigonal
ReplyDeletehardness
9
specific gravity
3,95-4,1
cleavage
Pseudo cleavage twinning
fracture
conchoidal
color
black
Color Powder
white
diamond gloss
Sulphur:
ReplyDeleteHardness - 1,5-2,5
Has a molecular lattice
Absence cleavage
Fragility
Rough break and the fat shine caused by it
On a surface of crystals glass shine
Relative density 2,07/sm3
Possesses bad electroconductivity
Weak heat conductivity
In low temperature of fusion (112,8°С) and ignition (248°С)
I apologise, has not noticed that is necessary jewels
ReplyDeleteAquamarine:
ReplyDeletea) mineral blue or bluish-green color, painted aquamarine usually evenly, but in some crystals observed zonal distribution of color
b) the hardness of 7.5-8 (Mohs)
c) the density of 2.75, but in spite of its hardness, aquamarine fragile and light,
d) transparent mineral, translucent, refractive 1,56-1,60,
e) the brilliance of glass, uneven to conchoidal fracture, cleavage imperfect, often noticeable transverse jointing, the hexagonal crystal system occurs as hexagonal prisms.
Vlad write please are the materials which you descibed mined with surface mining?
ReplyDeleteAquamarine is mined from pegmatites. A pegmatite is mined by open-pit mines.
Deletemagnetite
ReplyDeleteformula Fe3O4
cubic crystal system
Iron-black color
Black color features
Metallic luster
transparency is opaque
Hardness of 5.5 - 6
Cleavage is a very imperfect
fracture conchoidal
Density of 4.9 - 5.2 g / cm ³
The crystals of the cubic system (spinel). Color black. Gloss usually metal, but sometimes it is fat-tar or matte. Opaque. The hardness of 5.5-6. The density of 4,9-5,2. Sometimes there is an imperfect cleavage. Fracture conchoidal or uneven-step.
The powder is slowly soluble in HCl.
Has strong magnetic properties. Can change the compass. On this basis it can be found: the compass needle points to the magnetite and its deposits.
May deteriorate in the sand, which does not lose magnetic properties. When brought near the magnet magnetitny sand attracted to the poles of a magnet.
Blende
ReplyDeleteformula ZnS
Admixture of Fe, Cd, In, Ga
The cubic crystal system
Yellow, red-orange, green-yellow, gray, dark gray, almost colorless
Color features yellow to light brown
Diamond gloss
Transparency is transparent, translucent
Hardness of 3.5 - 4
Perfect cleavage
Fracture uneven, very fragile
Density of 4.08 - 4.10 g / cm ³
The refractive index of 2.368 - 2.371
Tetrahedral crystals. Birefringence and no pleochroism, dispersion 0.156. Luminescence is usually yellowish-orange, sometimes red, sometimes absent. Line absorption spectrum: 650, 665, 651 nm. Sphalerite structure was established by X-ray diffraction of the first one. composition (%): Zn - 67,1; S - 32,9.
Processed and polished with great difficulty because of the fragility and perfect cleavage in three directions. At first glance faceted sphalerite can be confused with gemstones yellow.
Cinnabar-HgS
ReplyDeleteCrystal system Trigonal
Color red, brown, gray
Color features bright red
Diamond Gloss or dim
Transparency is opaque, translucent in thin cleavages
Hardness 2 - 2.5
Perfect Cleavage
Fracture uneven, staggered, brittle
Density of 8.0 - 8.2 g / cm ³
The refractive index of 2.91
The most common mineral of mercury. Has scarlet coloring on freshly cleaved like blood stains. Gradually oxidized in air from the surface, covered with a thin film annealing (HgO).
Contains 85.83% mercury. It crystallizes in the trigonal system.
Characterized counterparts germination. Cleavage is perfect in one direction. Fragile.
Soluble only in aqua regia.
Quartz(SiO2)
ReplyDeleteColor - white or colorless
Transparency - transparent
Hardness - 7
Glitter - glass
Color features - white
Cleavage - imperfect
Specific Gravity - 2.65 -2.68
One of the most common minerals in the Earth's crust, rock-forming mineral bolshinstvamagmaticheskih and metamorphic rocks. Free content in the crust of 12%. Included in the other minerals in the form of mixtures and silicates. In total, the mass fraction of quartz in the crust more than 60%. In blood and plasma concentration of silica is 0.001% by weight.
Quartz
ReplyDeleteformula SiO2
Crystal system trigonal
Color Colorless, white, purple, gray, yellow, brown
White color features
Glitter Glass, in solid masses sometimes bold
hardness of 7
cleavage is imperfect
fracture conchoidal
2,6-2,65 density g / cm ³
The refractive index of 1.544
I decided to take a quartz because it is one of the most common minerals in the Earth's crust and as a crystal, quartz is
used as a semiprecious gem stone.
Cryptocrystalline forms may also
be gem stones: agate, jasper, onyx,
carnelian, chalcedony, etc. Crystalline
gemvarieties include amethyst,
citrine, rose quartz, smoky quartz,
etc. Because of its piezoelectric
properties quartz is used for pressure
gauges, oscillators, resonators,
and wave stabilizers; because of its
ability to rotate the plane of polarization
of light and its transparency in
ultraviolet rays it is used in heat-ray
lamps, prism, and spectrographic
lenses. Used in the manufacture of
glass, paints, abrasives, refractories,
and precision instruments.
Sorry for the repetition, but I was working, and if I tell you about another mineral.
ReplyDeleteChingiz,it's not a problem, you may describe the mineral that you like to describe. Thanks for your work
DeleteMalachite:
ReplyDeleteFormula Cu2 (CO3) (OH) 2
Crystal system monoclinic
color Green
Color green features of different shades, from turquoise to very dark, depending on the density of
Gloss Matt, in large quantities - glass, in crystalline form - silky
transparency is opaque
Hardness of 3.5 - 4
Perfect cleavage
Shelly fracture, splintery
Density of 3.75 - 3.95 g / cm ³
Form of separation of malachite in nature to be extremely diverse. Well-formed crystals are rare and always chalk, are columnar, plate, needle form, tend to split to form beams, fluffy balls.
Fluorite
ReplyDeleteChemical Symbol : CaF2
Color : white, green, blue, purple ; fluorescent light the stone purple rose
Streak : white, faintly purple
Transparency : transparent to translucent
Luster : glassy
Cleavage : perfect
Magnetism : not magnetically
Hardness : 4 ; Stone does not scratch the glass; mineral is brittle and soft
Specific gravity : 2.6-2.8 ;
Crystal shape : cubical
The stone used for the manufacture of medium-sized types of cookware, vases, boxes, as well as jewelry. He is often valued more than gold for its unique qualities and beauty. Fluorite used in optics, in the melting industry and jewelry. When heated in the dark glow.
Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and other faces.
ReplyDeleteColor Colorless (if no impurities), blue, brown, orange, gray, yellow, green, pink and reddish pink
Crystal habit Prismatic crystals with faces striated parallel to long dimension; also columnar, compact, massive
Crystal system Orthorhombic
Cleavage [001] Perfect
Fracture Subconchoidal to uneven
Mohs scale hardness 8 (defining mineral)
Luster Vitreous
Streak White
Diaphaneity Transparent
Specific gravity 3.49–3.57
Chalcopyrite
ReplyDeleteCategory Sulfide mineral
Formula
(repeating unit) CuFeS2
Strunz classification 02.CB.10a
Crystal symmetry Tetragonal 42m – scalenohedral
Unit cell a = 5.289 Å, c = 10.423 Å; Z = 4
Identification
Formula mass 183.54
Color Brass yellow, may have iridescent purplish tarnish.
Crystal habit Predominantly the disphenoid and resembles a tetrahedron, commonly massive, and sometimes botryoidal.
Crystal system Tetragonal Scalenohedral 42m
Twinning Penetration twins
Cleavage Indistinct on {011}
Fracture Irregular to uneven
Tenacity Brittle
Mohs scale hardness 3.5
Luster Metallic
Streak Greenish black
Diaphaneity Opaque
Specific gravity 4.1 – 4.3
Solubility Soluble in HNO3