What is the formula for 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.
Is olivine an Orthosilicate?
Olivines are a group of orthosilicate minerals of the general formula X2SiO4, where X is a divalent metal cation (Mg, Fe, Mn, Ni, Ca, and Co). Olivine crystal chemistry has been reviewed by Brown (1982).
Is olivine optically positive or negative?
By using optics, we have determined that olivine has n=1.635, is optically positive (if forsterite) and optically negative (if fayalite), has a 2V of ~85 degrees (if forsterite) and ~50 degrees (if fayalite).
Does olivine have any special properties?
Physical Properties of Olivine Olivine is usually green in color but can also be yellow-green, greenish yellow, or brown. It is transparent to translucent with a glassy luster and a hardness between 6.5 and 7.0. It is the only common igneous mineral with these properties.
What is the streak of olivine?
| Olivine | |
|---|---|
| Luster | Vitreous |
| Streak | None |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 3.2–4.5 |
Is olivine igneous metamorphic or sedimentary?
Olivine occurs in both mafic and ultramafic igneous rocks and as a primary mineral in certain metamorphic rocks. Mg-rich olivine crystallizes from magma that is rich in magnesium and low in silica.
Is olivine a cleavage or fracture?
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.
Is olivine toxic?
Olivine can contain toxic heavy metals such as nickel that could accumulate in the environment. Grinding rocks would produce dust, which might harm human health.
What is pyrite used for?
Pyrite is used to create iron sulfate that is used to make nutritional supplements, ink, lawn conditioner, water treatment and flocculation, moss killer, and many other chemical processes.
How is feldspar used?
The term feldspar encompasses a whole range of materials. Most of the products we use on a daily basis are made with feldspar: glass for drinking, glass for protection, fiberglass for insulation, the floor tiles and shower basins in our bathrooms, and the tableware from which we eat. Feldspar is part of our daily life.
Does olivine have a cleavage plane?
Olivine typically displays pale green pleochroism and no distinct cleavage.