What is Symplectite texture?
What is Symplectite texture?
A symplectite (or symplektite) is a material texture: a micrometre-scale or submicrometre-scale intergrowth of two or more crystals. Symplectites form from the breakdown of unstable phases, and may be composed of minerals, ceramics, or metals.
What type of rock is cordierite?
igneous rocks
Cordierite is a silicate mineral that is found in metamorphic and igneous rocks. It is typically blue to violet in color and is one of the most strongly pleochroic minerals.
Is cordierite a quartz?
Quartz is similar to untwinned cordierite but quartz is uniaxial (+). Cordierite often is slightly to completely altered, giving it a hazy or scuzzy appearrance; quartz does not alter. The four photos above are of a spectacular rock from near Kazabazua, Quebec.
How is Corona texture formed?
Corona texture: several concentric layers of one or more minerals completely encircling an older phase. A change in metamorphic conditions can give rise to porphyroblast growth, or to partial replacement of some minerals by others.
What is Corona texture?
Corona texture: several concentric layers of one or more minerals completely encircling an older phase. The layers (which range from one to five in number) represent a sequence of reactions that have taken place (none to completion) to replace the mineral in the core or center of the corona.
Which rock shows Ophitic texture?
Ophitic texture is the association of lath-shaped euhedral crystals of plagioclase, grouped radially or in an irregular mesh, with surrounding or interstitial large anhedral crystals of pyroxene; it is characteristic of the common rock type known as diabase.
Where do you find cordierite?
cordierite, also called dichroite or iolite, blue silicate mineral that occurs as crystals or grains in igneous rocks. It typically occurs in thermally altered clay-rich sediments surrounding igneous intrusions and in schists and paragneisses.
What is cordierite stone made of?
The cordierite stone is made from a blend of lead-free clay, which retains and evenly distributes heat well, plus it features raised edges on the bottom to make it easier to lift out of the oven.
Is cordierite an iolite?
cordierite, also called dichroite or iolite, blue silicate mineral that occurs as crystals or grains in igneous rocks. The natural mineral has little commercial use. When clear, cordierite is sometimes cut as a gem; the stones from the gem gravels of Sri Lanka have been called water sapphires.
What is the hardness of cordierite?
7 – 7.5Cordierite / Hardness (Mohs hardness scale)
What is Granoblastic texture?
Granoblastic is an adjective describing an anhedral phaneritic equi-granular metamorphic rock texture. Granoblastic texture is typical of quartzite, marble, charnockites and other non-foliated metamorphic rocks without porphyroblasts. A rock that has a granoblastic texture can be termed a granofels.
What causes Ophitic texture?
Keweenaw rift rocks include a somewhat rare textural variety of basalt called ophite or ophitic basalt. The rate of heat loss (undercooling or supercooling) during the solidification is thus thought to cause ophitic texture, where pyroxene is growing rapidly and plagioclase is forming many more nuclei.
What is cordierite stone used for?
Cordierite Stones. Cordierite is a mineral known for its ability to handle extreme temperatures well. It’s the same material they use to make kiln shelves, and it’s thermal shock resistant. This means you can take a cordierite stone from a low temperature to a very high temperature without the risk of breaking it.
What is the name of the element with the formula cordierite?
Cordierite, which was discovered in 1813, is named after the French geologist Louis Cordier, who first studied this species. Cordierite is always present as a solid solution between Mg-rich cordierite (Mg,Fe) 2 Al 3 (Si 5 AlO 18) and Fe-rich sekaninaite (Fe,Mg) 2 Al 3 (Si 5 AlO 18 ).
Is cordierite thermal shock resistant?
Cordierite is a compound mineral containing magnesium, iron, and more and when they are combined, they are known to retain high temperatures as well as cold ones. Cordierite stones are not perfectly thermal shock resistant but they can handle temperature changes better than the other stones that are available in the market right now.
How is cordierite formed in metamorphism?
In regional metamorphism, cordierite is formed only in environments where pressures are high and uniform. In these environments, the pre-existing minerals such as kyanite and biotite, become unstable reacting to give cordierite:
