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Inorganics

Id Identification Type Name Description Distinguishing Features Tags
115 Lithofacies Calcareous silt
38 Mineral Calcite Transparent colorless to pale greenish. High birefringence. Rhombic or ellipsoidal euhedra, corroded grains, micritic masses most common; more rarely twins, bow-ties, dendrites, sprays. Medium relief. Occurs as inorganic precipitate in lakes, in surface water and diagenetically (including as a replacement); also irregular detrital grains and rock fragments.

Organisms with calcite skeletal components include ostracodes, some molluscs, foraminifera, coccoliths, calcareous nannoplankton, Phacotus, charophytes, peloids, microbialites.
High-birefringence
Transparent
carbonate
Colorless
Rhombic
euhedral
salt
23 Mineral Chlorite Colorless to yellow or green, transparent, generally pleochroic. Low to moderate relief. Cleavage planes frequently visible as platy layers. Very low apparent birefringence (pseudo-isotropy) because flakes settle with {001} in the plane of the slide. However, by tilting the slide very slightly (e.g., by slipping another slide under the slide) one can evaluate the true birefringence (thanks to Frank Brown, U. Utah, for the tip). Chlorite has weak birefringence and can have anomalous (purplish or brown) interference colors due to its varying chemistry. Occurs as flakes larger than surrounding material when primary, can be fibrous or granular when replacing other minerals. Flaky
Pseudo-isotropic
yellow
green
layers
ragged
silicate
mica
transparent
low-birefringence
144 Contaminant Cigarette Ash contaminant
16 Mineral Clay
170 Lithofacies Clay turbidite cap
51 Mineral Clinoptilolite Associated with devitrified volcanic glass.
29 Mineral Clinopyroxene Transparent colorless to green or brown. May be pleochroic from yellow to green, depending on mineralogy. Moderate birefringence. Appear as stubby prisms and subhedral to anhedral crystals. Near-90 degree perfect cleavage. Moderately high relief. Subhedral
near-90-degree-perfect-cleavage
ferromagnesian
silicate
transparent
green
brown
pleochroic
moderately-high-relief
8 Mineral Cosmic Spherule