What are the properties of muscovite?
| Physical Properties of Muscovite | |
|---|---|
| Chemical Classification | Silicate |
| Mohs Hardness | 2.5 to 3 |
| Specific Gravity | 2.8 to 2.9 |
| Diagnostic Properties | Cleavage, color, transparency |
What does muscovite look like in thin section?
Muscovite and Biotite micas are easily indentified in thin section because they almost always exhibit “speckled extinction” in cross polarized light (see the top two and bottom two photomicrographs below). Usually, the perfect basal cleavage of the micas is evident in thin section.
How can you tell if a microscope is muscovite?
In general, keys to identifying muscovite are its low relief, lack of color, mica habit and cleavage, and second order interference colors. Color – usually colorless, less commonly pale green and slightly pleochroic. Habit and cleavage – often appears as tabs or long skinngy flakes which may be bent.
What is the crystalline structure of muscovite?
The green, chromium-rich variety is called fuchsite; mariposite is also a chromium-rich type of muscovite….
| Muscovite | |
|---|---|
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/c |
| Unit cell | a = 5.199 Å, b = 9.027 Å, c = 20.106 Å, β = 95.78°; Z = 4 |
What type of rock is muscovite?
metamorphic rocks
Muscovite typically occurs in metamorphic rocks, particularly gneisses and schists, where it forms crystals and plates. It also occurs in granites, in fine-grained sediments, and in some highly siliceous rocks. Large crystals of muscovite are often found in veins and pegmatites.
Is muscovite a mica?
muscovite, also called common mica, potash mica, or isinglass, abundant silicate mineral that contains potassium and aluminum. Muscovite is the most common member of the mica group. Muscovite typically occurs in metamorphic rocks, particularly gneisses and schists, where it forms crystals and plates.
How many planes of cleavage does muscovite have?
one cleavage plane
Mica (e.g. biotite, chlorite or muscovite) has one cleavage plane, feldspar (e.g. orthoclase or plagioclase) has two which intersect at 90°, and amphibole (e.g. hornblende) has two which do not intersect at 90°. Calcite has three cleavage planes which do not intersect at 90°.
Is muscovite anisotropic or isotropic?
Studies on the elastic behavior of muscovite revealed that some specimens were found to be elastically isotropic in the basal plane while some others exhibited pronounced anisotropy.
Is muscovite a cleavage or fracture?
Mica (e.g. biotite, chlorite or muscovite) has one cleavage plane, feldspar (e.g. orthoclase or plagioclase) has two which intersect at 90°, and amphibole (e.g. hornblende) has two which do not intersect at 90°. Calcite has three cleavage planes which do not intersect at 90°.
Is Muscovite metallic or nonmetallic?
| MINERAL NAME | LUSTER (appearance) | HARDNESS |
|---|---|---|
| Muscovite | Non-metallic (gold-clear) | Softer than glass |
| Fluorite | Non-metallic (purple, green, yellow) | Softer than glass |
| Calcite | Non-metallic | Softer than glass |
| Halite | Non-metallic | Softer than glass |
What are the physical and optical properties of Muscovite?
Optical Properties of Muscovite. Muscovite clear under PPL but with perfect cleavage and bright interference colours. Muscovite. Property. Value. Comments. Formula. KAl 2 (AlSi 3 O 10 ) (OH) 2. Solid solution mineral; substitutions can occur for K, [VI]Al, (OH) and in tetrahedral sites.
What are the diagnostic tags for Muscovite minerals?
The mineral’s lack of color, bird’s eye extinction and high birefringence are all diagnostic Add tags for Muscovite (thin section) Be The First. Post a Comment for Muscovite (thin section) Be The First.
What kind of mineral is found in muscovite rock?
Muscovite interspersed with chlorite (the brownish green pleochroic mineral) in plane polarized light. Magnification: 100x Rock: garnet mica schist To view t… Muscovite displaying its characteristic moderate birefringence and birdseye extinction in cross-polarized light.
What kind of alteration product is muscovite mineral?
Muscovite also originates as the alteration product of several other minerals, as topaz, kyanite, spodumene, andalusite, scapolite. Finite is a name given to the micaceous alteration product of various minerals, which corresponds in composition more or less closely to muscovite.