What is the cleavage of olivine?
What is the cleavage of olivine?
| Olivine | |
|---|---|
| Cleavage | Poor |
| Fracture | Conchoidal – brittle |
| Mohs scale hardness | 6.5–7 |
| Luster | Vitreous |
Which face shows cleavage in olivine?
Olivine typically displays pale green pleochroism and no distinct cleavage.
What is an olivine gabbro?
Gabbro: A coarse-grained plutonic rock composed essentially of calcic plagioclase, pyroxene and iron oxides. If the amount of orthopyroxene is more than 95% of the total pyroxene content then the rock is termed norite. …
Does olivine have high birefringence?
Olivine is in many ways similar to clinopyroxene. The keys to identifying olivine are its high birefringence, lack of cleavage (but often having fractures), and alteration. Important properties: Color – Usually colorless or very pale yellow.
What is the Colour and streak of olivine respectively?
10. What is the colour and streak of olivine respectively? Explanation: The olivine mineral is found in olive green colour and hence its name. The streak given by olivine is white.
What colors does olivine come in?
Olivine is an abundant silicate found in Earth’s mantle, and many meteorites contain this mineral. Olivine is typically olive green in color, but can also be yellow-green to bright green and brownish-green to brown.
What color is olivine in XPL?
olive-green
Olivine – named in allusion to its olive-green color.
What is the streak color of gabbro?
black
Gabbro is a coarse-grained, dark-colored, intrusive igneous rock. It is usually black or dark green in color and composed mainly of the minerals plagioclase and augite. It is the most abundant rock in the deep oceanic crust.
What is the color of gabbro rock?
dark gray
Gabbro is dark gray to greenish black color plutonic rock and chemically equivalent to volcanic basalt. The rock mainly contains Ca–plagioclase and ferromagnesian minerals such as pyroxene (augite and hypersthene or diallage) ± olivine.
What is the colour and Diaphaneity of a calcite mineral respectively?
What is the colour and diaphaneity of a calcite mineral respectively? Explanation: The calcite mineral is white in colour and its diaphaneity is transparent. The chemical composition of calcite is calcium carbonate.
What is the colour and Diaphaneity of a gypsum mineral respectively?
Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite, and dolomite….
| Physical Properties of Gypsum | |
|---|---|
| Chemical Classification | Sulfate |
| Streak | White |
| Luster | Vitreous, silky, sugary |
| Diaphaneity | Transparent to translucent |
What is the color of olivine?
olive green
Olivine is typically olive green in color, but can also be yellow-green to bright green and brownish-green to brown. The opacity of olivine ranges from transparent to translucent, and its texture is brittle with many fractures. Olivine is commonly associated with the green gemstone peridot.
What is the texture of olivine gabbros?
Most of the coarse-grained and pegmatitic olivine gabbros, however, have poikilitic or subophitic textures in which large subhedral poikilitic clinopyroxene (Fig. F5B) encloses or partly encloses small euhedral to subhedral plagioclase and, sometimes, olivine.
What type of alteration is found in olivine grains?
In thin section the large olivine grains exhibit black alteration minerals, such as hematite, along internal cracks, and dominantly green-coloured chlorite alteration at the grain margins. The pyroxene is also cracked but exhibits well-defined cleavage with some grains showing two cleavages at the characteristic 90 degree separation.
What is the age of this gabbro?
The rock is a plagioclase-olivine-augite cumulate gabbro and this example is about 489 million years old. In thin section the large olivine grains exhibit black alteration minerals, such as hematite, along internal cracks, and dominantly green-coloured chlorite alteration at the grain margins.
What colors do olivine grains show in XP light?
In XP light, the olivine can be seen to have 2nd order pastel interference colors that vary within individual grains. The largest olivine grain, a quarter of the way down from the top center of the photo) shows red, violet, blue and green interference colors.
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