Mineral Identification Flashcards
Metallic
opaque
reflects most light
Resinous
dull
waxy
Pearly
greasy
reflects some light
Adamantine
brilliant
high refractive index
ex: diamond
Vitreous
glassy
low refractive index
ex: quartz
Prismatic
well-developed pyramidal prism faces
Columnar
irregular prism faces
Acicular
needle-like
Botryoidal
rounded
blob/bubble-like
Tabular
flattened columns
plate-like
Stellate
radiating sprays of needles / fibers
Fibrous
parallel fibers
Dendritic
tree-like
7 Mineral Properties
- Crystal form and habit
- Luster and transparency
- Color and streak
- Cleavage, fracture, and parting
- Tenacity
- Density
- Hardness
Transparency
May be opaque, transparent, or translucent
Luster is a reflectance property that depends on the transparency of a mineral
Luster
Reflectance property based on the transparancy of a mineral
opaque minerals may appear metallic or dull and resinous
transparent minerals with a high RI appear brilliant and adamantine ex: diamond
transparent minerals with a low RI appear glassy and vitreous ex: quartz
Cleavage, Fracture, and Parting
In most xtals, atomic bonding is not of equal strength in all directions therefore, the weaker bonds tend to break along crystallographic directions giving them a fracture property that reflects the underlying structure.
perfect cleavage results in regular flat faces
less well-developed cleavage is **imperfect **
very weak cleavage is parting
if a fracture is irregular, it is hackly
conchoidal is an irregular scallop-shape
Tenacity
The ability of a mineral to deform plastically under stress
brittle - does not deform
sectile - may be cut with a knife
ductile - deforms readily
Density
g/cm3
density = mass / volume
Hardness
Mohs scale of Hardness
Approx. linear scale of standard minerals
- Talc
- Gypsum
- Calcite
- Fluorite
- Apatite
- Orthoclase
- Quartz
- Topaz
- Corundum
- Diamond
