1: The difference between olivine and pyroxene:

From the color point of view: olivine is emerald green, rich yellow-green, golden yellow-green; pyroxene is green-black or black.

In terms of cleavage: olivine has medium cleavage, incomplete cleavage, and high brittleness; pyroxene has complete cleavage and has two sets of parallel columnar cleavages with an intersection angle of 87 degrees

From the crystal structure: Olivine crystals are often short columnar and granular; pyroxene is a monoclinic or orthorhombic crystal system

1. Olivine: Olivine, a natural gemstone, its parent rock is the most important rock-forming rock in the earth's mantle Mineral, a silicate of magnesium and iron. The main components are iron, magnesium, and silicon, and can also contain elements such as manganese, nickel, and cobalt. The crystals are granular and appear as dispersed particles or granular aggregates in rocks. Belongs to island silicate. Olivine can be altered to form serpentine or magnesite, which can be used as a refractory material.

Color: emerald green, rich yellow-green, golden green

Mohs hardness: 6.5-8, slightly increases with the increase of iron content

Crystallization habit: Crystals are often short columnar and granular

Density: 3.3~3.5

Appearance: columnar or short columnar, often irregular granular

Application: Refractory materials

Cleaving: medium, incomplete, brittle

2. Pyroxene: It is a common single-chain structure silicate rock-forming mineral, widely found in In igneous rocks and metamorphic rocks, the main structure is composed of silicon and oxygen molecular chains. The pyroxene group minerals belong to chain-structured silicates and are one of the most important rock-forming minerals of crystallized salts.

Color: green-black or black

Hardness: 5.5-6

Crystal structure: monoclinic or orthorhombic

Cleaving: Complete cleavage, two sets of parallel columnar cleavages, with an intersection angle of 87 degrees

2: The difference between orthoclase and plagioclase:

From the color point of view : Orthoclase is often flesh-red, and plagioclase is gray-white

Different properties: Orthoclase is a monoclinic crystal system, and the crystals are short columnar or thick plates. Twin crystals are common, and some are granular or granular. Massive aggregate; plagioclase is a completely homogeneous series of Ab-An in the feldspar family of minerals, but it is immiscible with certain intervals at room temperature, forming a microscopic connection of two-phase feldspar. living body.

The physical properties are different: orthoclase is transparent, similar to topaz, yellow beryl, light yellow topaz or glass; plagioclase is white, gray and harder than a knife.

3. Orthoclase: It is a kind of feldspar and is an aluminum silicate of potassium. Orthoclase comes in many colors and is generally found in granite. Orthoclase is an important rock-forming mineral and is found in many rocks. Orthoclase can be used as a raw material for making glass and ceramics, and good-quality transparent orthoclase crystals can also be used as gemstones.

Cleaved: complete cleavage

Crystal habit: plate, prismatic

Crystal system: monoclinic

Hardness: 6-6.5

Category: Potash minerals

Distribution: in magmatic rocks and pyroclastic rocks with acidic and alkaline components

Gloss: light Blue

Stringes: White

Color: Colorless-White

4. Plagioclase: Plagioclase is a series of feldspar minerals. , including albite, feldspar, andesine, labradorite, feldspar and anorthite. Most varieties of plagioclase will produce fine and parallel stripes on the surface, and some will also have blue or green iridescence, which is caused by their twin crystal structure. The most common plagioclase is feldspar, the least common is feldspar.

Distribution: Widely distributed in igneous rocks, metamorphic rocks and sedimentary clastic rocks.

Uses: The main raw material of ceramic industry and glass industry. Those with beautiful and excellent color can be used as gemstone materials, such as sunstone.

Color: white or off-white. Hardness: Greater than a knife.

Clearment: Two sets of oblique complete cleavages.

Baidu Encyclopedia - Olivine

Baidu Encyclopedia - Pyroxene

Baidu Encyclopedia - Orthoclase

Baidu Encyclopedia - Plagioclase