Troilite

Troilite is a rare rock.

It is made of iron and sulfur. It does not act like a magnet. This is because it has a lot of iron.

You can find it on the Moon. It is also on Mars. Space probes have seen it there.

Most troilite comes from meteorites. One famous rock is from Canyon Diablo. Scientists use it to study sulfur.

It is very hard to find on Earth. It is much more common in space. It is a special piece of the stars.

Troilite is a rare mineral. It is made of iron and sulfur.

Some minerals in its group act like magnets. Troilite does not. This is because it has a lot of iron. It lacks the iron gaps that make other parts magnetic.

Finding troilite on Earth is very hard. Most of it comes from meteorites. A meteorite hit Russia in 2013. It also had troilite in it. One iron meteorite is named Mundrabilla. It has 25 to 35 percent troilite.

Troilite is much more common in space. It is the most common sulfide mineral on the Moon. Space probes saw it there. It is also found in rocks from Mars. It may even be in the cores of Jupiter's moons.

Scientists use a special troilite called CDT. It comes from the Canyon Diablo meteorite. They use it as a standard. This helps them study sulfur isotopes. Isotopes are different types of the same atom. The sulfur in meteorites stays very steady. This makes it a great tool for science.

Troilite is a rare mineral made of iron and sulfur. It belongs to a group called pyrrhotite. Most pyrrhotite has a tiny bit of iron missing. This missing iron makes pyrrhotite act like a magnet. Troilite is different because it has no iron gaps. Because it is full of iron, it is not magnetic.

This mineral has a very specific shape. It uses a hexagonal structure. You can think of it as two small units stacked on top of each other. The top unit is shifted slightly to the side. Scientists sometimes call this version pyrrhotite-2C. This shape helps define how the iron and sulfur atoms sit together. It is a very organized way for the atoms to be arranged.

We learned about this mineral through history. In 1766, a meteorite fell in Albareto, Italy. A man named Domenico Troili studied the iron sulfides inside it. For a long time, people thought it was a different mineral called pyrite. In 1862, a German mineralogist named Gustav Rose studied it closely. He saw it was a perfect 1:1 mix of iron and sulfur. He named it troilite to honor the work of Domenico Troili.

Finding troilite on Earth is quite a hard job. It is very rare in the Earth's crust. Most troilite on our planet comes from space. One iron meteorite named Mundrabilla has 25 to 35 percent troilite.

Troilite was also in a meteorite that hit Russia in 2013. It is common in meteorites from the Moon and Mars. Space probes like Apollo, Viking, and Phobos have confirmed it is on the Moon. It makes up about one percent of the lunar crust.

Scientists use a special type of troilite for important work. It comes from the Canyon Diablo meteorite. This is called Canyon Diablo Troilite, or CDT. Scientists use it as a standard to measure sulfur isotopes. Isotopes are different types of the same atom. Sulfur in meteorites stays very steady. This is different from Earth, where bacteria can change the sulfur. CDT helps scientists know when they are looking at space material.

Troilite is a rare iron sulfide mineral. Its chemical formula is FeS. This means it is made of iron and sulfur. It is the iron-rich version of a mineral group called pyrrhotite. Most minerals in the pyrrhotite group are iron deficient. This deficiency means they are missing some iron atoms. That missing iron is what makes most pyrrhotite magnetic. Troilite does not have this iron deficiency. Because it has a full amount of iron, troilite is non-magnetic.

At a microscopic level, troilite has a very specific hexagonal structure. Scientists use a Pearson symbol of hP24 to describe it. It also belongs to the space group P-62c. You can visualize its unit cell as two basic NiAs-type cells. These two cells are stacked vertically on top of each other. The top cell is diagonally shifted from the bottom one. Because of this unique stacking, troilite is sometimes called pyrrhotite-2C.

We have a fascinating history of discovering this mineral. In 1766, a meteorite fall happened in Albareto, Modena, Italy. A man named Domenico Troili studied the iron sulfide inclusions in that meteorite. For many years, people thought these inclusions were actually pyrite. Pyrite has a different chemical formula of FeS2. However, in 1862, a German mineralogist named Gustav Rose analyzed the material. He realized it was stoichiometric FeS, meaning it was a perfect 1:1 ratio. He named the mineral troilite to honor Domenico Troili.

Finding troilite on Earth is quite difficult. It is extremely rare in the Earth's crust. Most troilite found on our planet actually comes from meteorites. It can be found alongside minerals like daubréelite, chromite, and sphalerite. It also appears with graphite and various phosphates. In places like South Africa and Australia, it is found near copper, nickel, and platinum. Some rare Earth examples include the Alta mine in California and the Bushveld Complex in South Africa.

Space provides much more troilite than Earth does. The Mundrabilla iron meteorite contains 25 to 35 volume percent troilite.

Troilite is also found in the meteorite that struck Chelyabinsk, Russia, in 2013. It is a very common mineral on the Moon. It makes up about one percent of the lunar crust. Every rock brought back by the Apollo 11, 12, 15, and 16 missions contains about 1% troilite. It is also regularly found in Martian meteorites. These Martian samples also show a troilite fraction close to 1%.

Scientists use a specific type of troilite for very important measurements. They use troilite from the Canyon Diablo meteorite. This is known as Canyon Diablo Troilite, or CDT. CDT serves as the international standard for sulfur isotope ratios. An isotope is a version of an element with a different number of neutrons. The sulfur isotopes in meteorites stay relatively constant. This is different from Earth minerals, where bacteria can change things. Sulfate reducing bacteria, or SRB, can change the sulfur ratio. They can reduce 32SO4 2- much faster than 34SO4 2-. This can change the ratio of sulfur isotopes by up to 10%. Therefore, the ratio of 34S to 32S helps scientists identify microbial activity.

Beyond Earth and Mars, troilite might exist even further away. Observations from the Voyager spacecraft in 1979 and Galileo in 1996 suggest it might be in the rocks of Ganymede and Callisto. These are satellites of Jupiter. While we have very little experimental data for these moons, scientists use theoretical modeling. These models assume that the cores of these moons might contain about 22.5% troilite. This shows how a single mineral can help us understand the makeup of entire worlds.