| GRD020VS0 |
Augen Gneiss
|
Medium-sized sample of coarse-grained gneiss composed of potassium-feldspar-quartz-magnetite-biotite-garnet. Large potassium feldspar augen. One side of the sample is heavily weathered. |
|
0 |
Ritter 154, 24 A |
| GRD020WS0 |
Phyllite
|
Multiple samples of light green fine-grained phyllosilicates with quartz porphyroblasts. Foliated. Dull sheen. Billet. |
|
0 |
Ritter 154, 14 E |
| GRD020XS0 |
Blueschist
|
Small sample of glaucophane-calcite schist. Fine-grained dark blue glaucophane and thin calcite veins cross-cut the foliation. Original description: glaucophane rock. |
Mexico |
1 |
Ritter 154, 24 C |
| GRD020YS0 |
Folds
|
Quartz-mica-pyrite schist. Thin, well-formed, and bent banding. Cubic pyrite (rare). Very pronounced banding and hardness. Intense mylontization? |
Switzerland |
0 |
Ritter 154, 24 I |
| GRD020ZS0 |
Folds
|
Carbonate-biotite-quartz-amphibole-muscovite schist with folded laminae and ptygmatic folds. Melanocratic layers: biotite, carbonate, quartz. Leucocratic layers: carbonate, biotite, trace muscovite. Medium-grained quartz veins cutting across and along laminae. Marl protolith? Original description: Q-Bi gneiss with ptygmatic folds. |
|
1 |
Ritter 154, 14 P |
| GRD0210S0 |
Mafic
|
Altered mafic pegmatite. Coarse- to very coarse-grained. Hornblende-quartz. Miarolitic cavities are still present with nicely terminated crystals preserved. Original description: Metamorphosed pegmatite or granophyre of M50. Hbl-qtz-plag. |
New York |
1 |
Ritter 154, 14 H |
| GRD0211S0 |
Serpentinite
|
Small sample of serpentine replacing potassium feldspar. Gradational colors from brown-green-blue-purple-white. Original description: serpentine replacing feldspar. |
New York |
0 |
Ritter 154, 24 G |
| GRD0212S0 |
Serpentinite
|
Massive serpentine-talc rock. Dull dark green with thin white crystalline veins and small crystals of pyrite and large crystals of magnetite. Original label: verd antique. |
Vermont |
1 |
Ritter 154, 3 H |
| GRD0213S0 |
Serpentinite
|
Large sample of magnesite-bearing serpentine. Original label: Glenarm Serpentine; slickensides. |
Maryland |
1 |
Ritter 154, 14 M |
| GRD0214S0 |
Talc Schist
|
Medium-sized sample of talc-magnetite. Massive with little to no foliation. Original description: Soapstone. |
Virginia |
0 |
Ritter 154, 24 C |
| GRD0215S0 |
Serpentinite
|
Medium-sized sample of serpentinite that has a obvious distinction between the interior and exterior of the sample. The interior is very fine-grained and light green with abundant blue veinlets and magnetite crystals. The rim of the sample is blue while the exterior is light-green and golden serpentine with slickenslides. Antigorite? |
Canada |
0 |
Ritter 154, 24 G |
| GRD0216S0 |
Dolomite Marble
|
White, granoblastic dolomite marble. Faint spots of Fe-staining. Monomineralic. See also M-425. |
|
0 |
Ritter 154, 14 J |
| GRD0216S1 |
Dolomite Marble
|
White, granoblastic dolomite marble. Faint spots of Fe-staining. Monomineralic. See also M-425. |
|
0 |
Ritter 154, 24 E |
| GRD0217S0 |
Amphibole Schist
|
Amphibole-quartz-biotite-plagioclase schist. Faint foliation (slightly granoblastic). Mainly medium-grained. |
|
0 |
Ritter 154, 14 G |
| GRD0218S0 |
Non-layered Gneiss
|
Small sample of coarse-grained gneiss composed of potassium feldspar-quartz-muscovite. Discontinuous/lumpy banding (former augens?). |
Alpine |
1 |
Ritter 154, 24 A |
| GRD0219S0 |
Eclogite
|
Two small samples with black exteriors. A small cut surface reveals red anhedral garnets in a dark green fine-grained matrix. |
|
0 |
Ritter 154, 14 N |
| GRD021AS0 |
Relict Textures
|
Large sample is well-banded (quartz and fine-grained slate) and dense. Cryptocrystalline materials with soft-sediment type structures. Highly recrystallized (?). |
|
0 |
Ritter 154, 24 M |
| GRD021BS0 |
Migmatitic Gneiss
|
Very large polished slab. Original description: quartz-biotite-muscovite, Tephorite, Spessortite = lamprophyre, epidote veins. |
BK, NC |
0 |
Ritter 154, 14 R |
| GRD021CS0 |
Layered Gneiss
|
Slab of a gneiss with thin continuous bands. Phologopite- quartz-plagioclase (?). |
|
0 |
Ritter 154, 14 A |
| GRD021DS0 |
Augen Gneiss
|
Medium-sized sample of augen gneiss composed of potassium feldspar-quartz-biotite-amphibole. Sample has discontinuous banding and poorly developed augen. Melanocratic bands: biotite and amphibole; Leucocratic bands: Potassium feldspar and quartz. No rose quartz. Original description: Gneiss with rose quartz augen. |
California |
0 |
Ritter 154, 24 A |
| GRD021ES0 |
Layered Gneiss
|
Plagioclase-quartz-amphibole-biotite-garnet-pyrite (trace). Gradation from schist to gneiss. Gneiss has a slight augen texture. Pyrite and garnets are in leucocratic bands. See also M-111. |
California |
0 |
Ritter 154, 24 B |
| GRD021FS0 |
Schist
|
Large sample of tremolite schist. Well-foliated and coarse-grained. |
|
0 |
Ritter 154, 24 D |
| GRD021GS0 |
Layered Gneiss
|
Medium-sized sample of fine to medium-grained gneiss composed of biotite-quartz-plagioclase. Thick bands of biotite and amphibole with thin continuous and discontinuous bands of quartz and plagioclase (minor). Some green mineral (vesuvianite?) in the leucocratic layers. |
California |
0 |
Camp Elliott |
| GRD021HS0 |
Talc Schist
|
Small sample of chlorite-talc-muscovite (?). Foliated and medium to coarse-grained. Soapy feel. |
|
0 |
Ritter 154, 24 C |
| GRD021IS0 |
Schist
|
Slab of chlorite-quartz-magnetite schist. White delta-clasts (quartz) and euhedral black crystals (magnetite) in green fine-grained chlorite. Poorly foliated. Original description: Chl-Q-Mt metaconglomerate. |
|
0 |
Camp Elliott |
| GRD021JS0 |
Augen Gneiss
|
Polished samples of gneiss composed of potassium feldspar-quartz-biotite. Large potassium feldspar augen in melanocratic layer of biotite and quartz. No prominent banding |
|
0 |
Ritter 154, 14 B |
| GRD021KS0 |
Sedimentary Ore Deposits
|
Irregular banding. Amphibole (dark greenish?), calcite/carbonate, greenish epidote (?)/idocrase, quartz/plagioclase; Fe-hydroxide stains. Vulcan mine - contact metamorphic deposit of magnetite and hematite in Paleozoic carbonates associated with Mesozoic intrusion. |
California |
0 |
Ritter 154, 24 A |
| GRD021LS0 |
Pumice
|
Large (~9 cm in diameter), cut light grey pumice with billet. Original label: 20 November, 1980. |
Pacific Ocean |
1 |
Ritter 154, 37 B |
| GRD021MS0 |
Volcaniclastic Sediment
|
Small (5 cm in diameter) fine-grained rock with very fine-grained teal lithic fragments. Billet. Original label: 20 November, 1980. |
Pacific Ocean |
1 |
Ritter 154, 37 B |
| GRD021NS0 |
Scoria
|
Large (~8 cm in diameter) black-brown scoria. Vesicles become larger toward the center of the sample. Billet. Original label: 20 November, 1980. |
Pacific Ocean |
1 |
Ritter 154, 37 B |
