Rice-shape
Acicular
Elongate
High-birefringence
Acicular
Elongate
High-birefringence
Description
Transparent colorless. Nonpleochroic. Extreme birefringence. Distinguished by small (~10 um) acicular (needle-like) or rice-like grain morphology. Moderate relief, varying by direction. Twinning may be common.
Organisms such as pteropods, most mollusks, and some corals produce biogenic aragonite.
Transparent colorless. Nonpleochroic. Extreme birefringence. Distinguished by small (~10 um) acicular (needle-like) or rice-like grain morphology. Moderate relief, varying by direction. Twinning may be common.
Organisms such as pteropods, most mollusks, and some corals produce biogenic aragonite.
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