Minerals are defined as NATURALLY occurring crystalline solids. These come from the Earth, or meteorites or other natural systems.

Now, most minerals are compounds consisting of two or more elements. However some minerals are essentially elemental. Some examples are graphite C, diamond C (high pressure form of carbon) Native Fe, native Sulfur, gold Au, to mention some; these are elemental but they areminerals because they are found naturally.

Very interesting question about minerals, Valeria! As you know, minerals are naturally occurring inorganic solids that have a definite chemical composition, and a particular internal structure--that is, the atoms are stacked (arranged) in a very particular pattern.

In ice, a mineral, the water molecules become connected to each other through one kind of chemical bond (hydrogen bond-)-water molecules consisting of two hydrogen atoms, plus one oxygen. Minerals, like ice, are usually made of multiple elements, but sometimes of just one. A famous example of a single-element mineral is diamond, which is composed purely of the element carbon (C). So...most minerals are made of multiple elements, and therefore can be considered compounds. Minerals made up of a single element are more than simply that element, however. Diamond isn't the same thing as the element carbon, rather it's a solid in which a bunch of carbon atoms are arranged in a particular way. In other words, everything in diamond is carbon, but not everything carbon is diamond.

The word mineral comes from the Latin word minera, meaning mine. Minerals, obviously, are often extracted from the Earth in mines. The next question is where did the word mine come from---maybe we have a "what came first, the chicken or the egg type problem"? I leave this mystery for you to solve. Be well,

These are two very interesting questions! Before I can answer them, it’s important to mention what the exact definition of a mineral is. For something to be considered to be a mineral, it must:
1. Be a naturally occurring solid;
2. Have a well-defined chemical composition;
and
3. Have a specific crystal structure.

What I mean by a well-defined chemical composition is that a mineral is always composed of the same proportions of different elements. For example, the mineral quartz is always composed of silicon and oxygen, with there being two oxygen atoms to every silicon atom (SiO₂). When I say that a mineral has a specific crystal structure, what I mean is that the way that the atoms within a mineral are arranged is always the same, no matter where that mineral came from. For example, table salt, also known as halite, is a mineral composed of one sodium atom (Na) to every chlorine atom (Cl). In halite, these two atoms are always arranged such that they make crystalline cubes at the atomic level. This is why if you look at salt really closely, it’s made of a bunch of little cubes!

So to answer your first question, most common minerals on earth are composed of chemical compounds. However, minerals can also be made of single elements, as long as the three conditions above are met! Some examples include: diamond (C), gold (Au), silver (Ag), and tin (Sn). Most of the common minerals that are just composed of a single element are also metals, which are commonly mined for making jewelry, components in electronics, and many other things. This makes sense as the name ‘mineral’ comes from the Latin root ‘minera,’ which means ‘mine.’

Answer from our scientist.

Most minerals are compounds, made of two or more elements chemically bonded together. A few can occur as elements in nature. Gold is an example of a mineral that can occur in its elemental form, without chemically mixing with other elements. The roots of the word "mineral" go back a long way, to a time between 1066 AD and 1400 AD. Back then, a form of this word was used to mean something we can get by mining. By the early 1400s, it had taken on an expanded meaning of something inorganic that is neither animal nor vegetable. The definition of "mineral" used in modern science had appeared by the 1800s, to mean something inorganic, naturally occurring, with consistent chemical composition throughout, and of certain distinguishable characteristics (for example, an emerald is made of beryllium, aluminum, silicon, and oxygen in a defined ratio, looks crystalline, and green).

As to why we use the word "minerals", it's probably because of all of these reasons, and more:
1) When people from a long time ago saw these objects in mines, they decided to name the objects after the mines ("mine" and "mineral");
2) We have records of what people called them at that time ("minerals" in French/Middle English, as opposed to another word from another language) and have decided that it is easier to keep calling them by this name;
3) There hasn't been a need to change the name.

Hope these help - please let me know if there is anything unclear, especially the last answer. It was not a great leap to imagine that we could have called minerals something else if people from the Middle Ages decided to call them something else...I could not formulate my answer to "why are they called minerals" without considering how much written historical records have influenced present-day language, as well as how arbitrarily some words might have been formed...

First, what are minerals? According to the International Mineralogical Association (a.k.a IMA), a mineral must:
1. Be naturally occurring and formed by natural geological compounds. Things made exclusively by humans or living beings, therefore, do not count. If geological processes are involved after creation by living beings, they may still qualify as a mineral. Things that have yet to be found also don't count, even if we predict their existence.
2. Be a solid substance when found naturally (except for mercury). Interestingly, this means that water when found as a liquid is not considered a mineral. However, if you find water as ice, it is considered a mineral.
3. Have a well-defined crystal structure. This means their atoms have to be arranged in a tidy, orderly manner, with repeating patterns.
4. Have a fairly well-defined chemical composition. The elements that make up the mineral are in specific ratios.

Not everyone agrees with the IMA though! There's a lot of controversy surrounding (1), with a lot of people arguing that living organisms are capable of forming minerals.

Based on the above, you can see that minerals can be either elements or compounds. Uncolored diamonds, for example, are minerals that are made up of only carbon atoms arranged in a crystal structure called "diamond cubic". An example of a mineral made of a compound is salt, or sodium chloride. This is the same salt that flavors your food and makes you float more easily in the ocean than in a lake.

Finally minerals are so called in English because we took it from Old French's mineral, which got it from medieval Latin's minerale, a derivation of the Latin word minera meaning "ore".

Materials that are called minerals are all compounds.

A compound is a cluster of atoms of different elements that, in most cases, has a so-called crystal structure. A crystal structure describes the way of how the atoms in a compound are arranged. The result of this crystal structure can sometimes even be seen with the bare eye. Snowflakes, which are little ice crystals, form in their special shapes because of the crystal structure of the ice crystals. In fact, ice crystals are also considered minerals because they have a defined composition of elements and a defined crystal structure. Therefore, minerals are classified as compounds with a certain crystal structure, a well-defined chemical composition, and as compounds that naturally occur in their pure form.

The two most common minerals on earth are quartz and talc. Quartz has the chemical formula SiO₂ and consists of the elements silicon and oxygen. Talc is a little more complicated with formula Mg₃Si₄O₁₀(OH)₂. A chemist would call it a hydrous magnesium silicate.

The word mineral comes from the Latin word "minerale" which refers to a "substance obtained from mining" or more simply to "something mined". Therefore, these materials are called minerals because they can be mined from earth.

Some minerals are elements (e.g. graphite, diamond, sulfur), but most are compounds.

A mineral is any naturally-occurring crystalline substance. Normally, we don't think of organic compounds (containing carbon) as minerals, such as the crystallized protein that makes up the lens in your eye, but carbonate minerals (calcite, aragonite, dolomite) still are regarded as minerals, and they do contain carbon, probably because they are found in rocks, while proteins are not.

On Earth, we don't normally think of water ice as a mineral, even though there is every reason to, and on other planets, it certainly is.

Both elements and compounds can be minerals.

A mineral is a solid, inorganic, naturally occurring, crystalline substance with a fixed chemical composition.

Diamond is pure carbon, so it is a mineral made of only one element. On the other hand, calcite is a mineral which contains carbon, as well as calcium and oxygen. The word mineral comes from the Latin word minera, meaning ore or mine.

Geological minerals can be either elements or compounds. Elements comprise only a single atomic species while compounds are combinations of 2 or more elements. Compounds make up a larger fraction of all minerals though. Single-element minerals are primarily unreactive metals (mostly gold, silver, copper, and platinum) and carbon compounds (coal). These elements are also found in compounds. Every mineral has a specific composition (combination of elements), even when made of multiple elements. The term "minerals" comes from the Latin word for mine or ore and apparently is used because many minerals are mined.