What elements make up olivine?
Olivine incorporates only minor amounts of elements other than oxygen (O), silicon (Si), magnesium (Mg) and iron (Fe). Manganese (Mn) and nickel (Ni) commonly are the additional elements present in highest concentrations.
What is the olivine group?
Olivine is the name of a group of rock-forming minerals that are typically found in mafic and ultramafic igneous rocks such as basalt, gabbro, dunite, diabase, and peridotite. They are usually green in color and have compositions that typically range between Mg2SiO4 and Fe2SiO4.
What other minerals are found with olivine?
The composition of common olivine minerals are listed below:
- Forsterite: Mg (2) SiO (4)
- Fayalite: Fe (2) SiO (4)
- Monticellite: CaMgSiO(4)
- Tephroite: Mn (2) SiO(4)
What is the rock type for olivine?
Olivine is most commonly found in igneous rocks of low silica content, such as basalts and gabbros, and is occasionally found in metamorphic rocks.
What is the chemical structure of olivine?
Olivine is a magnesium iron silicate with the formula (Mg2+, Fe2+)2SiO4. End members are forsterite (Mg2SiO4) and fayalite (Fe2+2SiO4). Olivine is an abundant mineral in most mafic igneous rocks and the most abundant mineral in the earth’s upper mantle. It has an orthorhombic crystal system.
Which elements are part of the silicate mineral known as olivine?
The simplest silicate structure, that of the mineral olivine, is composed of isolated tetrahedra bonded to iron and/or magnesium ions.
What is the cleavage of olivine?
Cleavage and fracture – Olivine has one very poor cleavage not seen in thin section; instead grains typically fracture in an irregular manner.
Is olivine a feldspar?
Feldspars are the most abundant minerals in the Earth”s crust. They are silicate minerals and are referred to as framework silicates because the tetrahedra (of Si and Al four coordinated by oxygen) are linked together in three dimensions to make a framework….Feldspar.
| HARDNESS | 6-6.5 |
|---|---|
| SPECIFIC GRAVITY | 2.56-2.76 |
Which igneous rock is entirely composed of olivine mineral?
troctolite, coarse-grained, intrusive igneous rock that is composed almost entirely of olivine (often iron-rich) and plagioclase feldspar (labradorite or bytownite).
What are the properties of olivine?
Olivine Physical Properties
| Chemical Classification | Silicate |
|---|---|
| Cleavage | Poor cleavage, brittle with conchoidal fracture |
| Mohs Hardness | 6.5 to 7 |
| Specific Gravity | 3.2 to 4.4 |
| Diagnostic Properties | Green color, vitreous luster, conchoidal fracture, granular texture |
What is olivine silicate structure?
The simplest silicate structure, that of the mineral olivine, is composed of isolated tetrahedra bonded to iron and/or magnesium ions. In olivine, the –4 charge of each silica tetrahedron is balanced by two divalent (i.e., +2) iron or magnesium cations.
What type of silicate structure does olivine have?
Olivine is one of the minerals on Earth that is made up of the simplest silicate structure – and these minerals are called nesosilicates. Nesosilicates are minerals in which single tetrahedrons are isolated from each other by metallic cations.
How many cleavage does olivine have?
Interference colors – Interference colors may range up to strong third order. Cleavage and fracture – Olivine has one very poor cleavage not seen in thin section; instead grains typically fracture in an irregular manner.
Is a olivine cleavage or fracture?
Diagnostic Features: Distinguished usually by its glassy luster, conchoidal fracture, green color, and granular nature….Olivine Physical Properties.
| Chemical Classification | Silicate |
|---|---|
| Diaphaneity | Transparent to translucent |
| Cleavage | Poor cleavage, brittle with conchoidal fracture |
Is olivine a quartz?
Olivine is typically with pyroxenes (in basalt, for example) and quartz + K-feldspar with micas (biotite and muscovite) is a typical composition of granite. But there are no such rock types that are composed of olivine plus quartz.
What might be the origin of a rock composed almost entirely of olivine?
The origin of a rock composed almost entirely of olivine would be from a magma that is at high temperature and is enriched in iron and magnesium. The olivine-rich rock likely formed by fractional crystallization early on in the cooling process.
What are olivine crystals?
An olivine crystal is normally a roundish lump 2 mm or less across. A mass of pure olivine crystals thus forms a distinctive granular texture. Olivine’s color ranges from the deep green of peridot to the olive green of olives to the pale olive green of pale green olives.
Which of the following is a member of the silicate mineral group?
The vast majority of the minerals that make up the rocks of Earth’s crust are silicate minerals. These include minerals such as quartz, feldspar, mica, amphibole, pyroxene, olivine, and a great variety of clay minerals.
What is the calcium rich end member of the feldspar plagioclase called?
Albite
Albite (NaAlSi3O8—usually designated Ab) and anorthite (CaAl2Si2O8—An) are end-members of the plagioclase series.
Does olivine have a cleavage?
Olivine typically displays pale green pleochroism and no distinct cleavage.