Rating
Name	Apatite (thin section)
Type	Mineral
Cleavage	Not observed in thin section
Colour and Pleochroism	Most commonly colorless in thin section; Grains from deeply colored specimens may exhibit pale coloration; Weak to moderate pleochroism possible if colored
Relief	Moderate to high positive relief
Form	Usually occurs as euhedral to subhedral grains with a prismatic habit and hexagonal cross sections; Acicular habit common in igneous rocks; Anhedral grains, granular and columnar aggregates also common
Optical Orientation	Parallel extinction
Twinning	None
Birefringence, δ	δ = 0.001- 0.007; Maximum interference colors generally first order grey, basal sections may appear isotropic
Optical Character	Uniaxial (-)
2V	n/a
Key Characteristics	Moderate to high relief, lack of color, low birefringence and uniaxial character are key features
Photograph Comments	pic 1(left): plane polarized light, magnification 100x, arrows refer to basal sections of subhedral grains displaying hexagonal outline; pic 2(right): cross polarized light, magnification 100x, arrow refers to basal section with vertical optic axis resulting in an isotropic appearance
Hand Sample URL	http://digicon.athabascau.ca/u?/RM,93
Subject	Minerals; Rocks; Identification photographs; Geology;
Date	2009
Format	image/jpeg
Identifier	2009-rm-0001
Collection Title	Rock and Mineral Samples
Repository	AU Digital Library
Rights	Subject to the Copyright Act

Apatite (thin section)

Description