| GRD020DS0 |
Lineation
|
Original description: sheared Pre-Cambrian granite in shear zone of Adirondacks; N40E, 20, E-W 30 ? |
New York |
1 |
Ritter 154, 14 P |
| GRD020IS0 |
Amphibole Schist
|
Multiple small samples of amphibolite. Generally amphibole-potassium feldspar-quartz-pyrite- epidote (rare). Mineral assemblage depends on individual sample. |
New York |
0 |
Ritter 154, 14 G |
| GRD020JS0 |
Amphibole Schist
|
Amphibole-garnet-mica schist. Abundant garnets (many are approximately 4 mm in diameter) in amphibole matrix. Sample is capped by thin layer of fine-grained phyllosilicates (phyllite?). The contact between phyllite and amphibolite is Fe-stained. |
|
0 |
Ritter 154, 3 G |
| GRD020KS0 |
Crenulation Cleavage
|
Quartz-plagioclase-muscovite-biotite gneiss with folds (crenulation cleavage) with slight lineations. Well-developed foliation and thin continuous bands. |
California |
1 |
Ritter 154, 24 I |
| GRD020LS0 |
Layered Gneiss
|
Fine-grained (cryptocrystalline) gneiss with folds and augen. Quartz-pyroxene-pyrite (rare). Foliated with continuous thin bands- relict bedding/laminations (?). |
|
1 |
Ritter 154, 14 B |
| GRD020MS0 |
Quartzite
|
Dark grey quartzite with some Fe-oxide stains along fractures. Somewhat sugary appearance. |
|
0 |
Ritter 154, 24 F |
| GRD020NS0 |
Serpentinite
|
Green serpentinized rock; Small, rounded light green clasts (relict olivine?) and a few thin black minerals (magnetite?) in a dark green matrix. Original description: verde antique |
Mexico |
0 |
Ritter 154, 3 G |
| GRD020OS0 |
Serpentinite
|
Two small cut samples. Both are sheared. The slightly larger sample has dark green clasts in a light green matrix. Abundant serpentine on the surface. The smaller sample has dark blue clasts in a light grey matrix. The sample has muscovite on the surface. Billet. Original description: sheared serpentine rock. |
Mexico |
1 |
Ritter 154, 14 M |
| GRD020PS0 |
Serpentinite
|
Small dark green serpentinite sample. Vitreous luster. |
|
0 |
Ritter 154, 24 G |
| GRD020QS0 |
Serpentinite
|
Large sample mainly composed of serpentine and clay minerals. There is an obvious distinction between the core of the sample and the rim. The core is very fine-grained light green with thin blue veins. The rim is composed of vitreous light to dark green serpentine with a soapy/greasy feel. Serpentized, altered ultramafic rock. |
|
0 |
Ritter 154, 14 M |
| GRD020RS0 |
Calcsilicate (Skarn)
|
Contact/gradation between metapelite (fine-grained, quartz and phyllosilicates) and medium-grained skarn (poorly formed/preserved amphibole and garnet in granular/sugary quartzite matrix). |
South Dakota |
0 |
Ritter 154, 14 K |
| GRD020TS0 |
Augen Gneiss
|
Large sample of a gneiss composed of biotite- potassium feldspar- quartz- pyrite (rare). Potassium feldspar augen and no banding. The largest augen has a bleb of pyrite inside. Original description: Augen gneiss. Microcline porphyroblasts replacing metagreywacke. Qtz-biotite-garnet-microcline. Granulite facies. |
New York |
0 |
Ritter 154, 24 A |
| GRD020US0 |
Non-layered Gneiss
|
Medium-sized slab of fine-grained gneiss composed of quartz-biotite-garnet. Some relict grains. No banding. Original description: metagreywacke; waltons QBG; Qtz-biotite-garnet. |
|
0 |
Camp Elliott |
| 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 |
