Geology:Lab 2-Minerals
what is luster?
Luster is the appearance of a minerals surface in reflected light
What is a mineral?
Mineral is a naturally occurring solid, formed by geological processes, that has formed a crystalline structure and deniable chemical composition
what is a crystalline structure?
a crystalline structure is the atomic structure of a mineral that is fixed in a certain pattern.
what is it called when where cleavage breaks
a fracture
what is a minerals streak.
a minerals streak is the powder color of a mineral
define celevage
a place in which a mineral breaks to form a distinct planar surface
an example of a luster adjectives if a nonmetallic mineral is dull and earthy
clay
what is crystal cleavage
cleavage is the the way in which crystal breaks
what does color result from in a mineral
color results from the interaction the mineral has with sun light
what are the two main properties that create shape in a crystal
crystal habit and cleavage
what is crystal habit a result of
crystal habit is a result of its specifically ordered arrangements of atoms, all minerals, when allowed unrestricted space in grow, will develop geometrically arranged sets of smooth planar faces.
what is a crystal habit
crystal habit is the shape that crystal grows
crystalline is is a material in which atoms are fixed in an orderly pattern, which mineralogist reefer to this pattern as a .....
crystal-lattice
a octahedron constitutes a crystal habit
eight-sided form with faces that are equilateral triangles
In terms of color what types of streaks do minerals make
either a distinct or white color or no color at all
an example of a luster adjectives if a nonmetallic mineral is vitreous
plastic or glass
an example of a luster adjectives if a nonmetallic mineral is silky
silk
a rhombohedron constitutes a crystal habit
six-sided form with faces in the shape of rhombus
which one has more variability in color the color of the mineral or the streak
streak
some minerals that have board line metallic trates are called
sub metallic
a cube constitutes a crystal habit
that is a six-sided form with a square face
what does cleavage tell us
the direction in which a mineral breaks tells us were it is weak
what are the face of crystals habits
the faces are characteristic for each mineral and constitutes its crystal habit
what is the hardness of a mineral determine
the hardness is a measurement of a minerals ability to resist scratching
what type of streak do minerals with metallic luster typically have
the type of minerals typically yield black or dark colored streaks
how are crystal habits named
they are named based on their geometric shape
what type of streaks do minerals with nonmetallic luster have
they have translucent or transparent and usually have colorless or light-colored streaks
when describing things using color. always remember what?
to describe it with the combination of something else
a dodecahedron constitutes a crystal habit
tweleve-sided form with diamond-shaped faces
a pyritohedron constitutes a crystal habit
twelve-sided form with faces having the shape of a pentago
what is the mores common category type do nonmetallic minerals have
vitreous or glassy
a mineral absorbs certain...., so the color you see when looking at a specimen represents the....the mineral does not absorbs
wavelengths
an example of a luster adjectives if a nonmetallic mineral is resinous
yellow resin or pitch
Is a minerals streak more reliable then crystals ?
yes, minerals powder tends to have less variables than the color of a who crystal thus it gives a fairly reliable clue to a mineral's identity
how can you determine the hardness of two minerals? The mineral that gets scratched is...
you can determine the hardness of two minerals by scratching them toghther and the one that gets scratched is softer
What two things do you need to know about the geology of an area?
1.) what minerals are present? 2.) How are those minerals organized in the rock?
a scalenohedron constitutes a crystal habit
form whose faces are in the shapes of scalene triangles
a prism constitutes a crystal habit
group of faces with three,four or six sides having parallel intersection
what is a crystalline solid?
is a material in which atoms are fixed in an orderly pattern
what type of physical properties do look at when we are studying minerals
luster,color, streak, hardness, geometric form,cleavage and other features
what type of luster are minerals that look like metals (opaque,shiny) have
metallic luster
an example of a luster adjectives if a nonmetallic mineral is pearly
mother of pearl
Minerals who don't have an opaque shinny look have what type of luster
nonmentallic
an example of a luster adjectives if a nonmetallic mineral is greasy
oily glass