Mineralogy 3rd set
serpentine
Appearance: Opaque to translucent, light, soft, infusible, and susceptible to acids Lustre: Vitreous, silky, or greasy Structure: Microcrystalline and massive, never found as single crystals Color: Usually green, yellow, and black Inclusions: Magnetite, chromite, or other minerals Fracture: Flexible (antigorite) or uneven (chrysolite) Texture: Mesh-like, visible with polarized light. fibrous . 2.5-4
olivine
Chemical Composition(Fe,Mg)2SiO4), Iron - Magnesium SilicateColorPale olive green to yellow-green, occasionally brown.CleavagePoor cleavage in two directions at 90 degrees.Hardness6.5 to 7 (very hard)Specific Gravity3.2 (Mg-rich variety) to 4.3 (Iron-rich variety) (average weight)
Plagioclase
Chemical CompositionRanges from NaAlSi3O8 (Albite) to CaAl2Si2O8 (Anorthite)Hardness6 to 6.5 (harder than glass)Specific GravityIncreases from 2.6 to 2.8 depending on amount of calcium.LusterIncreases from 2.6 to 2.8 depending on amount of calcium.StreakWhite
Labradorite
Chemical Formula:(Ca,Na)(Si,Al)4O8Diaphaneity:Translucent to transparentFracture:Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.Habit:Crystalline - Coarse - Occurs as well-formed coarse sized crystals.
Hornblende
Color: Black, dark green, brown, or opaque green Luster: Vitreous, submetallic, or dull Transparency: Generally opaque, but thin crystals or exceptional specimens can be translucent Hardness: 5-6 on the Mohs scale of mineral hardness Specific gravity: 3.0 to 3.6 Crystal system: Monoclinic; 2/m Cleavage: Imperfect in two directions at 56 and 124 degrees Fracture: Uneven
Andalusite
Color: Greenish brown, yellowish green, pinkish brown, orangy brown, white, gray Hardness: 6.5 to 7.5 on the Mohs scale Density: 3.1 to 3.2 Fracture pattern: Uneven or partially conchoidal Cleavage: Good to poor Luster: Vitreous
Jasper
Color: Usually red, yellow, brown or green in color; and rarely blue. Luster: Dull vitreous to greasy . Transparency: Translucent to opaque. Crystal System: Hexagonal-R; 32 (trigonal-trapezohedral) Crystal Habits: Massive microgranular quartz.
Enstatite
Color: White, yellowish green, brown, greenish white, or gray Density: 3.1-3.3, average = 3.2 Diaphaneity: Translucent to opaque Fracture: Brittle Hardness: 5.5-6.5 on the Mohs scale Cleavage: Perfect in two directions at 90 degrees Luster: Vitreous
Zircon
ColorColorless, yellow, brown, orange, red, violet, blue and greenHardness6-1/2 to 7-1/2 (Mohs)Specific Gravity3.93 - 4.74
Amazonite
ColorPastel blue-green, Deep green/blue (Russian)Hardness6 (Mohs)Specific Gravity2.5 - 2.6Refractive Index1.522 - 1.530
Muscovite
ColorUsually colorless, white or silver, occasionally yellow or brown.CleavageSingle perfect cleavage to produce thin sheets or flakes.Hardness2 to 2.5 (very soft)
Silimanite
HabitAcicular Long, slender prisms Fibrous Subparallel aggregates and splays Fine-grained fibrous matsColorWhite to brownHardness6 to 7Specific gravity3.23
Potassium Feldspar
Hardness6 > GlassCleavageYes Prismatic at right anglesStreakNoneColorPink or White
Wollastonite
Hardness: 4.5-5 on the Mohs scale Density: 2.86-3.09 Streak: White Color: White, gray-white, light green, pinkish, brown, red, yellow Lustre: Vitreous, pearly
chert
Hardness: Chert has a hardness of seven on the Mohs scale. It's as hard as crystalline quartz. Fracture: Chert breaks with a conchoidal (shell-shaped) fracture. This creates very sharp edges that don't dull easily. Texture: Chert has a smooth, non-clastic sedimentary texture. Luster: Chert has a waxy luster.
Prehnite
Hardness:6-6.5 - Orthoclase-PyriteLuminescence:Fluorescent, Short UV=blue white mild peach, Long UV=yellow.Luster:Vitreous - Pearly
augite
Mohs scale hardness 5.5 to 6 LusterVitreous, resinous to dullStreakGreenish-whiteDiaphaneity
biotite
highly perfect basal cleavage, and consists of flexible sheets, or lamellae, which easily flake off.
Chlorite
typically green in color, have a foliated appearance, perfect cleavage, and an oily or soapy feel.