Think you know rocks, minerals and gemstones?

The three types of rock are igneous, metamorphic and sedimentary. Minerals, on the other hand, are actually not rocks at all.

Rather, they are naturally occurring solid substances that are distinguished for their specific chemical composition and crystalline structure. A rock can contain one or more minerals, and in some cases, no minerals at all.

Travertines are a type of limestone formed by mineral springs. The distinctive "terrace" appearance is created by the swift precipitation of calcium carbonate, which is one of the primary minerals that makes up limestone.

You're no fool if you picked pyrite! Despite its resemblance to gold, this brassy, pale yellow mineral is actually iron-based. Because of this, it is commonly known as "fool's gold."

Igneous rocks like pumice, basalt and obsidian are all formed through volcanic activity.

Gneiss, on the other hand, is formed by metamorphism and is known for its distinctive banding composed of pre-metamorphic sedimentary and igneous rocks.

Those brilliant, diffracting specks of light found within an opal are determined by the internal structure of each gem.

A staggering 90 percent of all the world's opals are found in Australia. It also happens to be the place of origin for the "Virgin Rainbow," which is touted as the world's finest opal.

Although they are both composed of carbon, the idea that diamonds are formed from coal is actually a myth. Their origin stories are quite different in both time and scale.

Coal is a fossil fuel that is formed over millions of years from dead carbon-based lifeforms (primarily plants). On the other hand, diamonds, which are created from pure carbon sources, take billions of years to develop under intense metamorphic pressure.

Mica is a lightweight and relatively soft mineral characterized by its flaky silicate sheets. There are actually 37 different types of mica — the specimen pictured above is known as muscovite.

Talc has a rating of "one" on Mohs' Scale of Hardness, and because of its physical qualities, it is often utilized in powder form as a deodorant or as a method for preventing diaper rash.

Constituting about 60 percent of all terrestrial rocks, feldspar is the most abundant type of mineral found within the Earth's crust. It is often found mixed with other minerals in rocks like granite.

For the better part of the 20th century, asbestos' fibrous crystals were widely used as an affordable, fire-resistant insulation material in building and manufacturing. After discovering that the mineral was causing chronic respiratory diseases like lung cancer and mesothelioma, the mineral (pictured above as a solid lump) was gradually phased out.

Today, if homeowners or developers want to renovate or demolish a property built prior to the 1980s, they must take extra precautions to do so safely.

By definition, all minerals are inorganic and possess a crystal structure. However, coal is a non-crystalline rock made up of organic carbon-based lifeforms. It is sometimes referred to as amorphous carbon, which means that it doesn't have a crystalline structure (unlike carbon minerals such as graphite or diamond).

Other examples of organic rocks and gems include amber (fossilied tree resin), coprolite (fossilized feces) and coquina (limestone composed of shells and coral).

Diamonds are still one of the hardest materials in the world, but in recent years, scientists have made several new advances. This includes the development of a man-made material known as aggregated carbon nanorods (ACNR), which is capable of scratching diamonds. Even so, we won't see diamonds going away anytime soon — they're still heavily depended upon for industrial cutting.

Tiger's eyes are quartz gemstones that are known for their silky reddish-brown chatoyancy — a reflective optical effect created by the stone's fibrous structure. The word "chatoyancy" comes from the French phrase "œil de chat," which means "cat's eye."

Identified by its hexagonal crystal formations, pure beryl is colorless, but when it is tinted by impurities, it can take on colors like green, blue, yellow and red.

Turquoise is an opaque, blue-green mineral that is composed of copper and aluminum. As one of the first gems ever mined by humans, it has a long history as a prized ornamental gem.

The Navajo sandstone found within this iconic slot canyon was carved into its distinct, wavy shape over many years through erosion caused by flash floods.