What Is a Gemstone?

Often referred to as gems, gemstones are minerals that can be cut into beautiful and unique pieces. They are also a valuable commodity to geologists. They have been used since ancient times, and even today, people continue to mine them in remote regions. They are generally durable, and can withstand chemical weathering. They also retain their polish, and are resistant to constant handling. Some gems are colored, and the color may be an important deciding factor in choosing a particular gemstone.

There are many different types of gemstones, and they are all categorized by their crystal system and their naming scheme. The most common varieties are diamonds, emeralds, and rubies. Some are naturally formed, and others are man-made. They are also grouped into species, which describe the mineral they are composed of. In addition to their names, they are sometimes accompanied by pictures or videos. Regardless of the type of gem, the main requisite for a gem is the beauty of the stone, the quality of the material, and the rarity of the source.

There are several types of gems, including transparent and opaque ones, and each has their own unique attributes. For example, a stone may have a large amount of inclusions, or have an interesting absorption spectrum. The color of the stone may also play a part in determining its value. Some gemstones have been heated, removing undesirable hues. This is often done to make sapphires and emeralds more transparent. Other treatments manipulate the impurities in the gem, or change its composition.

There are also synthetic gems, which are made from chemicals or other compounds. For instance, a lab-created stone might be free of natural impurities, and have a more colorful, and therefore more valuable, appearance. Some of these materials, such as emeralds, can sell for more than $1 million per carat.

There are a few different fabrication methods, and the most common of these is faceted cutting. This involves a series of facets, each of which is cut to a specific angle. The facets are designed to maximize the reflected light, or brilliance, of the gemstone. The other types are the step cut and drop cut. Some cutters use special curved laps to cut curved facets. The most popular faceted stones are the brilliant cut and the rose cut.

Another interesting gem is the iris agate. This is a colorful gemstone that produces a rainbow of colors when light passes between thin bands. It can be found in Russia, Yukon Canada, and Myanmar. It is a very interesting material that is worth the effort to see.

There are numerous other gems, including zoisite, azurite, chrysoberyl, sugilite, and apatite. Some gems are formed in gas bubbles in volcanic rocks, and others crystallize from a solution. Some are created inside the earth itself, and others are made from living organisms. There are also synthetic gems, such as emeralds and sapphires. Some are even crafted from plant or animal materials.