Enstatite

This mineral is found in many rocks.

It can be white, gray, or brown. Some parts are green. These green parts make it a pretty gem.

It is also found in space. You can find it in meteorites. It is even in some stars. This rock helps us learn about space. It is a very special find.

Enstatite is a type of mineral. It is part of a group called pyroxenes. These minerals help make many different rocks.

You can find enstatite in igneous rocks. These are rocks made from hot, melted material. It is also in metamorphic rocks. These rocks change when they are squeezed or heated.

Enstatite can be many colors. It is often white, gray, or brown. Some parts are green. This green kind is called chrome-enstatite. It is a gemstone.

Other kinds look like bronze. This is called bronzite. It happens when the mineral changes over time.

This mineral is also found in space. It is in many meteorites. Scientists see it in space outside our solar system too. It is found near some stars. It is also in clouds around a young brown dwarf. A brown dwarf is a small, dim star. Enstatite helps us learn about how rocks form in space. It is also a main part of E-type asteroids. These are rocks that float in space.

Enstatite is a special kind of mineral. It belongs to a group of minerals called pyroxenes. This mineral is part of a series that changes based on what is inside it. One end of the series is enstatite, which is rich in magnesium. The other end is called ferrosilite, which is rich in iron. Scientists use these names to show how much of each part is present. For example, they might write En80Fs20 to show a mix. This mineral is very important for making rocks. It is found in many igneous and metamorphic rocks.

There are different ways this mineral can form. Most natural crystals have an orthorhombic shape. This means they have a specific crystal structure. Sometimes, the mineral changes depending on heat and pressure. High temperature and low pressure create forms called protoenstatite and protoferrosilite. Low temperature forms are called clinoenstatite and clinoferrosilite. These have a different shape called monoclinic. When enstatite weathers, it can change its look. It might take on a bronze color and a metallic shine. This version is called bronzite, but it is actually just altered enstatite.

People have known about these minerals for a long time. Varieties like bronzite and hypersthene were known before enstatite was named. A scientist named G. A. Kenngott first described enstatite in 1855.

Some types of enstatite are used as beautiful gemstones. One variety is called chrome-enstatite because it is emerald-green. This green color comes from small amounts of chromium. Other types are used as semi-precious stones too. These can look black or even brownish.

Enstatite is found in many different places on Earth. It is a main part of the Earth's mantle. You can find it in rocks like peridotite and pyroxenite. It also appears in volcanic rocks like basalt and andesite.

In 1874, very large crystals were found in Norway. These crystals were a foot long! They were found near the Kjørstad apatite mine. Scientists also study enstatite in meteorites that fall to Earth. It can be found in stony and iron meteorites. One such meteorite fell at Breitenbach in the Ore Mountains of Bohemia.

This mineral is also a traveler in space. It is a common mineral in many meteorites. Scientists have even seen it outside our Solar System. It can be found around evolved stars and planetary nebulae like NGC 6302. It is also a main part of E-type asteroids. Some asteroids, like the one named Steins, help us learn more. Enstatite might be one of the first ways crystals form in space. It might even exist in clouds around a young brown dwarf. This helps us understand how the universe builds rocks.

Enstatite is a vital rock-forming mineral. It belongs to the pyroxene silicate group. This group includes a series of minerals that change based on their chemical makeup. Enstatite is the magnesium endmember of this series. This means it is the version that contains the most magnesium. Its chemical formula is MgSiO3. The other end of the series is ferrosilite, which is FeSiO3. Ferrosilite is rich in iron instead of magnesium.

Scientists study how these two minerals mix together. This mixture is called a solid solution series. The composition is often written using relative proportions. For example, En80Fs20 means the mineral is 80% enstatite and 20% ferrosilite. Historically, intermediate compositions were called hypersthene. That name has been formally replaced by the term orthopyroxene. This helps scientists be more precise when they identify minerals. Understanding these proportions helps geologists understand how rocks formed.

Enstatite can change its crystal structure. These different forms are called polymorphs. Most natural crystals are orthorhombic. This refers to their specific geometric shape. High temperature and low pressure create protoenstatite and protoferrosilite. These are also orthorhombic. However, low temperature forms change their structure. These are called clinoenstatite and clinoferrosilite. These forms are monoclinic, which is a different crystal shape.

Weathering can also change the appearance of the mineral. When enstatite weathers and gains a small amount of iron, it changes. It develops a submetallic luster and a bronze-like color. This material is called bronzite. Scientists now say bronzite is actually just altered enstatite. People knew about bronzite and hypersthene long before enstatite was named. The scientist G. A. Kenngott first described enstatite in 1855.

Some varieties of enstatite are used as gemstones. One variety is called chrome-enstatite. It is an emerald-green color. This color comes from small traces of chromium. Other types are used as semi-precious stones. These include black, chatoyant hypersthene and brownish bronzite. Enstatite itself can be white, gray, greenish, or brown. It has a hardness of 5–6 on the Mohs scale. Its specific gravity is 3.2–3.3.

Enstatite is found in many geological environments. It is an essential part of the Earth's mantle. In the mantle, it is found in rocks like peridotite and pyroxenite. It is often close to an En90Fs10 composition. It also appears in igneous rocks like gabbro and diorite. It can form small crystals in volcanic rocks like basalt, andesite, and dacite. In 1874, researchers found massive crystals in Norway. These crystals were a foot in length. They were found in apatite veins near Brevik.

This mineral is also important for studying space. Enstatite is a common mineral in meteorites. It appears in both stony and iron meteorites. One notable meteorite fell at Breitenbach in the Ore Mountains of Bohemia. In some meteorites, it forms small spherical masses called chondrules. It can also be found in the atmosphere of the young brown dwarf 2M2224-0158. There, it may exist in clouds of quartz and enstatite.

Beyond our Solar System, enstatite is very significant. It is one of the few silicate minerals seen in crystalline form in deep space. It is observed around evolved stars and planetary nebulae like NGC 6302. It is also a main component of E-type asteroids. The Hungaria asteroids are a major example in our Solar System. Scientists believe enstatite represents an early stage for crystalline silicates in space. Studying its chemistry helps researchers reconstruct the depths of the Earth's mantle.