The 20 types of gemstones (described and with pictures)

Rubies, sapphires, emeralds, diamonds, agates... there are many stones that decorate high-end jewelry and costume jewelery, associated with beauty, various meanings and even mystical powers.

There are many types of precious stones if any mineral that seems beautiful to the naked eye is considered as such, although in many cases it is actually semi-precious stones.

Next we will delve into the types of gemstones that exist, what criteria are used to incorporate them into this group and we will also see other minerals of great beauty and hardness.

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Characteristics of precious and semi-precious stones

Precious and semi-precious stones are highly coveted items, especially in the world of jewelry. Precious stones due to their color, scarcity and beauty they are highly sought after in different fields, being the main jewelry business although we can also observe them in electronics, shaping electronic devices, and also in alternative therapies, New Age movements and beliefs mystical.

Before finding out which are the main gemstones, it should be clarified that, although used interchangeably, the terms gemstone and gem are not the same. We understand gems as a broader group of minerals and similar substances that can be divided into two large groups: precious stones and semi-precious stones. In order for a mineral to be classified as a precious or semi-precious stone, it must meet the following properties.

1. Beauty

Precious and semi-precious gems They are because they have beauty, manifested in the form of unique colors, transparency or brightness. Sometimes, to get a mineral to become something beautiful it is necessary to apply some type of chemical that highlights some of its physical properties, a fundamental aspect in the jeweler's.

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2. Durability

Durability has to do with the toughness of the stone, that is, how difficult it is to scratch it with another mineral or how resistant it is to shock and pressure. You can also check the resistance of the stone by applying chemicals on it and seeing how it resists over time.

Generally, the hardest stones, that is, those that are higher on the scale of stone hardness are considered precious stones, being led by diamond.

3. Colour

Color is considered, along with beauty, one of the fundamental characteristics for a gem to be considered precious or semi-precious. The most sought-after gems are usually those with beautiful colors, such as greens, reds, and blues., while the least coveted are white, transparent and black, except if they are diamonds that are seen as the most beautiful gemstone by many people.

4. Shine or luster

The luster or luster is the physical property that refers to how the stone reflects light on its faces. In gemology, luster includes reflection, refraction, scattering and faceting of the light that falls on the stone.

The easier it is for light to pass through the glass, the stone is considered to be of better quality, while the more opaque the mineral, the less value it will have. The brightest stones are those that are considered precious stones.

5. Rarity or scarcity

The more scarce a mineral is, the more price it will have in the jewelry market. This shortage may be due both to the very scarcity of the mineral on the face of the earth and to the difficulty that it supposes to be able to obtain it.

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The main types of gemstones

There are different ways of classifying precious and semi-precious stones, mostly of mineral origin, although there are also those that come from living beings, such as amber and pearls. Here we will focus on the two broad categories into which we can divide them.

Gemstone varieties

It may surprise more than one, but there are really only four types of pure gemstones.: diamond, ruby, sapphire and emerald. A few decades ago amethyst was also included in this classification as a precious stone but, when enormous deposits of this mineral in Brazil, its price decreased as it was no longer so rare and it was considered a stone semi-precious.

1. Diamond

The diamond It is the hardest known natural substance on planet Earth, with a value of 10 on the Mohs scaleA striking property, but it is not the only one that makes it stand out from other stones, since this mineral also has the peculiarity of being made of a single element: carbon.

Although we generally think of diamonds as transparent and white stones, the truth is that they can come in a wide spectrum of colors. Colored diamonds are called "fancy," with blue and pink being the rarest, while yellow and brown are the most common.

2. Ruby

The name of the ruby ​​comes from the Latin “ruber”, which means red, alluding to its main physical characteristic. Its red color is intense and bright due to the metals that make up this mineral, iron and chromium.

Rubies belong to the corundum family along with sapphire, and have a hardness of 9 on the Mohs scale, making it the second hardest gemstone.

Normally, when extracted from nature, this mineral has a rough and unattractive appearance, but once working on it, it becomes a highly valued gem in the jewelry market, adopting a reddish hue radiant.

3. Blue sapphire

The blue sapphire belongs to the corundum family, like the ruby ​​and, in fact, it could be considered that they are rubies only that of blue tones. While it is true that there are sapphires of other shades, the blues are the most coveted for their unique beauty and rarity.

Any corundum of a color other than red is called sapphire, which is why the blue ones are accompanied by the adjective "blue" to distinguish them from others, which can be orange, pink, gray, black, brown, purple and green. Blue sapphire has the same hardness on the Mohs scale as ruby, 9.

4. Emerald

The name of the emerald comes from the Greek "smaragdos" which is believed to be a linguistic loan taken from some Semitic language in which that word should literally mean "green stone", alluding to its striking colour. This mineral belongs to the beryllium family and has a hardness of 8 on the Mohs scale.

Emeralds have always been highly valued because, Despite the existence of other green stones, this one stands out for being a very crystalline mineral.. Although other green crystalline stones are known today, none stands out as much as emeralds, with unparalleled colors and transparency.

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Varieties of semi-precious stones

Semi-precious stones are minerals, organic stones and mineraloids that they have some characteristic that makes them beautiful, but not as beautiful as precious stones. In addition, although they are rare substances, they occur in greater quantities in nature than diamonds, rubies, sapphires and emeralds.

The prices of semi-precious stones are very different, fluctuating according to various conditions such as hardness, rarity and beauty. There are approximately 130 mineral species classified as semi-precious, in addition to amber and pearls, which, as we have said, are of organic origin. The most used in jewelry are the following.

1. Amethyst

As we have said before, the amethyst was considered a gemstone a while ago, but after a significant amount of this mineral was discovered in mines in Brazil, it became a more common stone, causing it to become part of semi-precious stones.

But although it has lost value, it is still the most sought-after variety of quartz in the jewelry market due to its purplish-purple color, highly valued as a gem. It can also be yellow or even transparent, depending on the amount of iron it contains. Its hardness on the Mohs scale is 7.

2. Agate

Agate is a variety of chalcedony, which can have various shades and colors, as well as being transparent, semi-transparent or opaque. Its physical characteristics are determined by the formation of silica microcrystals. Its name comes from the Greek "Achates", the name that the Sicilian river Dirillo received in Hellenistic antiquity and has a hardness on the Mohs scale of 7.

That its name is related to a river is not by chance, since agates are formed by the action of groundwater that, being near silicon saturations, fill rock cavities with that substance, in addition to shells and bones. It is by this process that agates are formed with concentric bands, similar to the rings of tree trunks.

3. Aquamarine

Aquamarine It belongs to the beryl family, just like emerald, and could be considered a variant of that gemstone only with a pale greenish-blue hue. Its name is due to the fact that it is reminiscent of the color and brightness of sea water. It has a hardness of 8 on the Mohs scale.

4. Alexandrite

Alexandrite is a very rare variety of chrysoberyl with a soft green or greenish yellow color. The most relevant property of this semi-precious mineral is its ability to change shades and color when different beams of light affect it., going from green to red.

This stone was discovered in the time of Tsar Alexander II, which is why it is called like that and also becoming a kind of patriotic symbol because this mineral has the same colors as the flag of Russia Imperial. Its hardness on the Mohs scale is 8.

5. Amber

Amber or succino is a stone of organic origin. Its most common name comes from Arabic and means "what floats in the sea" since, in effect, amber floats in sea water. Its most common color is yellow, although there are also orange and reddish colors..

It is formed from fossilized plant resin, from conifers such as pine, which has hardened over time. Some very valuable pieces of amber may be sixty million years old or more, but for They are usually quite soft minerals, with a hardness of 2.5 on the scale of Mohs.

6. Aventurine

Also called as aventurite quartz, aventurine has various shades of green although it can appear with reddish, brown and yellow tones due to the inclusions of other minerals. Its most appreciated visual characteristic, in addition to color, is its interior sparkle when light falls on it.. It has a hardness of 7 on the Mohs scale.

7. Quartz

Quartz, also called rock crystal, has as its main properties its transparency and low cost., being a mineral widely used both in high costume jewelery and in jewelery.

It is formed from the slow crystallization of residual magmas and has a hardness of 7 on the Mohs scale.

8. Smoky quartz

Smoky or smoky quartz is a compound of silica that has various shades of brown, from light to very dark, having a hardness of 7 on the Mohs scale. It has a special variety of brown color called morion.

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9. Peridot

The peridot or olivine, in the past known as the gem of the sun, is composed of magnesium, iron and silicone. Its most appreciated color is olive green, although it is also found in other colors such as yellow, pistachio green and brown. It has a very intense luster, it is frequently found in volcanic rocks and it has a hardness of 6.5 on the Mohs scale.

10. Garnet

Garnet has a dark reddish color, although it is also can present shades of orange, green, yellow and black. It is a mineral belonging to the family of aluminum silicates combined with iron and magnesium oxide, which are what give it this reddish garnet color.

Its cost is quite low because it is found in large proportions in nature, being a substitute for ruby ​​because it has a similar color but is much cheaper. Its hardness is 7.5 on the Mohs scale.

11. Topaz

Topaz is a semi-precious stone widely used in jewelry, both for its beauty and for its hardness of 8 on the Mohs scale. We find it in blue, yellow, pink, smoky and the rarest and most valued variety is the imperial topaz, orange and reddish yellow in color.

12. Turquoise

Turquoise is a greenish-blue stone that is made up of alumina phosphate with a mixture of copper and iron.

Its name refers to the fact that it comes from Turkey, even though the Turks actually simply made intermediaries between Asia and the Middle East, from where this mineral was extracted, with the West, where arrived. It is a stone with the peculiarity of being porous, so it needs certain care. It has a hardness of 5.5 on the Mohs scale.

13. Jasper

Jasper is a mineral belonging to the quartz or chalcedony family, but it is mixed with iron oxide. Is about an opaque stone that we can find with different colors such as dark green, yellow or brown, the most valuable being red or blood jasper. It has a hardness of 6.5 on the Mohs scale.

14. Opal

Opal is a very rare variety of quartz, which can be opaque or translucent and come in different colors such as white, gray, blue, black or orange. It has the property of having a play of colors inside, an effect that is due to the diffraction of light that passes through its silicon microparticles, which project colors pure spectral. It has a hardness of 6 on the Mohs scale.

15. Lapis lazuli

Lapis lazuli is part of the silicates, mixed with sulfate of lime and soda with small incrustations of pyrite and iron. It is a mineral with a very intense blue color, used to make necklaces and bracelets.

In the past it was a highly valued mineral and until the 19th century it was used as a pigment to obtain the blue color of oil paint. It has a hardness of 5.5 on the Mohs scale.

16. Onyx

Onyx is an opaque variety of agate, made up of striped quartz. It presents dark and black colors, although there are also light and reddish tones. The varieties of this mineral that are not black in color are known as sardonyxes. Its name comes from the Greek "onyx" which means "nail", a name associated with the Greek myth that When Cupid cut Venus's nails while he slept, they fell to earth in the form of this mineral. It has a hardness of 7 on the Mohs scale.