What is the texture of andesite rock?
Porphyritic Andesite
| Type | Igneous Rock |
|---|---|
| Texture | Porphyritic |
| Origin | Extrusive/Volcanic |
| Chemical Composition | Intermediate |
| Color | Dark Green |
What is the texture and color of andesite?
Andesite is the volcanic equivalent of diorite. Group – volcanic. Colour – variable, but typically bluish-grey or grey (lighter coloured than basalt). Texture – porphyritic.
Is andesite coarse grained?
Andesite is a fine-grained rock that forms when the magma erupts onto the surface and crystallizes quickly.
What is the crystal texture of andesite?
Andesites are medium to dark coloured vesicular volcanic rocks, mostly fine grained with typically porphyric texture (larger crystals in a fine groundmass). The phenocrysts (the larger crystals) comprise plagioclase, pyroxene, biotite and iron-titanium oxides. The groundmass is fine-grained, frequently glassy.
What is the texture of granite rock?
Phaneritic
Granite
| Type | Igneous rock |
|---|---|
| Texture | Phaneritic (Coarse-grained) |
| Origin | Intrusive/Plutonic |
| Chemical Composition | Felsic |
| Color | Predominantly white |
What does andesite look like?
Andesite is a fine-grained, extrusive igneous or volcanic rock. It is dark grey and made up of equal amounts of light and dark minerals, although the crystals are too small to be seen without a magnifier. Occasionally andesite may contain some larger crystals. Or small round pockets that were gas bubbles.
Is andesite hard or soft?
The hardness of andesite rocks on the Moh scale is 7.
What are the characteristics of andesitic rocks?
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava. The mineral composition of andesite includes biotite, pyroxene, or amphibole.
What are the characteristics of andesite?
What texture is basalt?
Porphyritic
Porphyritic Basalt
| Type | Igneous Rock |
|---|---|
| Texture | Porphyritic |
| Origin | Extrusive/Volcanic |
| Chemical Composition | Mafic |
| Color | Dark Gray to Black |
What igneous rock has a glassy texture?
Obsidian
Obsidian is the common rock that has a glassy texture, and is essentially volcanic glass. Obsidian is usually black.
How to identify andesite?
Andesite is usually light to dark gray in colour, due to its content of hornblende or pyroxene minerals. but can exhibit a wide range of shading. Darker andesite can be difficult to distinguish from basalt, but a common rule of thumb, used away from the laboratory, is that andesite has a color index less than 35.
Is andesite a rock or a mineral?
Andesite is the name of a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. They have a mineral composition that is intermediate between granite and basalt. Andesite is a rock typically found in volcanoes above convergent plate boundaries between continental and oceanic plates.
Is andesite mafic or felsic?
Andesite is INTERMEDIATE in composition between MAFIC and FELSIC rocks. The mixture of mafic and felsic minerals gives the rock a ‘salt and pepper’ appearance. ANDESITE – aphanitic rock (small crystals) of both mafic and felsic minerals.
What is andesite used for?
Uses of Andesite It is fairly strong, which allows it to be used in road and railway construction, and as fill gravel. The grayish colored rocks seen between railway ties are often andesite or its close relative, basalt. Perhaps the most interesting use of andesite is as proof of volcanic activity on Mars.