Mineralogy Lab

Front 1

PP light

Back 1

only able to see extinction, which is when a mineral turns darker or black with the rotation of the microscope stage

Front 2

XP light

Back 2

inteference colors only seen under

Front 3

Opaque minerals

Back 3

do not transmit in thin sections. So, they appear black on both the XP and PP lights at all times

Hint 3

Graphite
Magnetite

Front 4

Isotropic minerals

Back 4

minerals that have the same properties in all directions. So light passes through them in the same way, with the same velocity, no matter in what direction light is traveling

Hint 4

Garnet
Spinel

Front 5

Anisotropic minerals 1

Back 5

have different properties in different directions. So lights travels though in different ways and in different velocities, depending on direction of travel though a grain

Front 6

Anisotropic minerals 2

Back 6

90 degree extinction of pleochroism under PP light

Front 7

Anisotropic minerals 3

Back 7

biaxial, two optic axises where light does not split

Hint 7

Orthorhombic
Monoclinic
Triclinic

Front 8

Anisotropic minerals 4

Back 8

uniaxial, one optic axis where light does not split

Hint 8

Tetragonal
Hexagonal

Front 9

Index of refraction

Back 9

The ratio of the speed of light in a vacuum to the speed of light in a medium under consideration

Front 10

Angle of extiction

Back 10

measure between the cleavage direction

Front 11

Thin section 1

Back 11

a laboratory preparation of a rock, mineral, soil, pottery, bones, or even metal sample for use with a microscope.

Front 12

Thin section 2

Back 12

A thin sliver of rock is cut from the sample with a diamond saw and ground optically flat.

Front 13

Thin section 3

Back 13

It is then mounted on a glass slide and then ground smooth using progressively finer abrasive grit until the sample is only 30 μm thick.

Front 14

Pleochroism

Back 14

is an optical phenomenon in which a substance appears to be different colors when observed at different angles, especially with polarized light.