Question Three The diagnostic properties of minerals in transmitted light microscopy are essentially influenced by the atomic structure of minerals under investigation. Transmitted light microscopy uses several of these diagnostic properties such as refraction, extinction, interference, birefringence, anisotropism or isotropism, twinning, zonation, color and pleochroism, refractive index, cleavage etc. to identify minerals. Clearly explain each of the listed diagnostic properties and use your labeled microscope above to explain how you can generate or isolate or view or observe them under the microscope. Question Four The Polarizing Microscope uses two types of light to identify the diagnostic properties of minerals: Plane Polarized Light (PPL) or Cross Polarized Light (XPL). Distinguish the two types of light, stating the relevance of each type in transmitted light microscopy. Of the diagnostic properties listed in Question Three above, identify the properties that can be viewed under PPL and XPL, respectively. Of what significance would you use XPL and PPL on a named mineral specimen?.

1. Question Three The diagnostic properties of minerals in transmitted light microscopy are
essentially influenced by the atomic structure of minerals under investigation. Transmitted light
microscopy uses several of these diagnostic properties such as refraction, extinction, interference,
birefringence, anisotropism or isotropism, twinning, zonation, color and pleochroism, refractive
index, cleavage etc. to identify minerals. Clearly explain each of the listed diagnostic properties
and use your labeled microscope above to explain how you can generate or isolate or view or
observe them under the microscope. Question Four The Polarizing Microscope uses two types of
light to identify the diagnostic properties of minerals: Plane Polarized Light (PPL) or Cross
Polarized Light (XPL). Distinguish the two types of light, stating the relevance of each type in
transmitted light microscopy. Of the diagnostic properties listed in Question Three above, identify
the properties that can be viewed under PPL and XPL, respectively. Of what significance would
you use XPL and PPL on a named mineral specimen?