Precious Stones and Gems

Precious Stones and Gems are pieces of crystallized minerals, organic rocks, and artificial materials, which are used in jewelry and other forms of adornment after getting cut, carved and polished. A precious stone is also known as gemstone, gem, jewel and semi-precious stone.

Some may differentiate between precious and semi-precious. Diamonds, rubies, sapphires and emeralds are known as precious stones, and the rest as semi-precious.

However, due to the rarity and an increase in demand of some of these semi-precious stones, they are now all considered precious.

Today more than 300 types of gemstones have been found in nature, and even though they are the most used stones in jewelry, there are other kinds of material as well. We can categorize all the precious stones and gems them in five:

  • Minerals
  • Organic Materials
  • Synthetic Materials
  • Precious Rocks
  • Chatoyant Gems

There are a series of factors that make a gemstone valuable, such as: Rarity, Clarity, Beauty and Hardness. The people who determine these values are called lapidaries or gem cutters, except for diamonds. Those who work with diamonds are known as diamantaires.

In this post, we are going to learn about the most precious gems and stones used in jewelry, that fall under the categories above.



Category: Native Mineral

Colors: Transparent, yellow, grey (typical) – Blue, pink, black, violet (rare)

Hardness: 10 (Hardest natural material on earth)

Chemical Formula: C (100% pure Carbon)

Price: 3,000$ – 30,000$ per carat

Most Found: Russia, South Africa, Botswana

We are beginning with the most valuable gemstone. Diamond is the solid form of element carbon arranged in cubic crystal structure. It has the highest hardness and thermal conductivity among all materials.

Diamonds are one of the oldest material that existed on earth, dating back to 3.5 billion years. Due to its amazing clarity, diamond also has a high optical dispersion, meaning it reflects the most colors of a light ray. Diamond is also the birthstone of April.

Due to its incredible rarity on earth, and the highest demand in the jewelry industry and many other, synthetic diamond has been made over the years. The type of diamond is either created by experimenting on carbon elements in the lab, or is in the form of cubic zirconia or silicon carbide.

The most famous diamonds are:

  • The great star of Africa (530.2 carats)
  • The Orloff (300 carats)
  • The Centenary Diamond (273.85 carats)
  • The Regent (140.5 carats)
  • Koh-i Noor (105.6 carats)



Category: Oxide Mineral

Colors: Shades of Red

Hardness: 9

Chemical Formula: Al2O3:Cr (Aluminum oxide with repeating chromium)

Price: 20,000$ – 50,000$ per carat

Most Found: Afghanistan, Australia, Brazil, Columbia

Ruby comes from the Latin word “ruber”, which means red. Various concentration levels of chromium element is responsible for its color. Similar to diamond, this mineral is valued upon cut, clarity, carat and color. The Sunrise Ruby is the world’s most precious ruby.

After diamond and moissanite, rubies are the hardest mineral in the world. Spinels are often found alongside rubies, and due to their similar color, they are usually mistaken for one another. Ruby is the birthstone of July.



Category: Oxide Mineral

Colors: Blue, pink and yellow (rare)

Hardness: 9

Chemical Formula: Al2O3 (Aluminum oxide – repeating unit)

Price: 30$ – 1,200$ per carat

Most Found: Afghanistan, Sri Lanka, Madagascar, Myanmar, Tanzania

Sapphire is a precious gemstone and another variety of the mineral corundum like ruby. Corundum is the crystalline form of aluminum oxide with traces of iron, titanium, vanadium and chromium.

Unlike rubies, sapphires are common and affordable. Besides jewelry, they are applied in glass windows, semiconducting circuits, lasers and medical fields as well. Sapphire is the birthstone of September.

Notable sapphires of all times are:

  • Star of Adam (1404.5 carats)
  • Black Star of Queensland (733 carats)
  • Star of India (563.4 carats)
  • Queen Marie of Romania (478.68 carats)
  • Logan Sapphire (423 carats)



Category: Beryl Mineral

Colors: Shades of Green

Hardness: 7.5 – 8

Chemical Formula: Be3Al2(SiO3)6 (repeating unit)

Price: 500$ – 1,000$ per carat

Most Found: Columbia, Zambia, Afghanistan

Emerald is a cyclosilicate, part of a rock-forming mineral that makes up 90% of earth’s crust in total. Its green color comes from the concentration of chromium or sometimes vanadium elements. Emeralds are also easily broken. It is the birthstone of May.

The most famous emeralds in the world are:

  • Bahia emerald (180,000 carats)
  • Chalk emerald (38.4 carats)
  • Duke of Devonshire emerald (1383.9 carats)
  • Gachala emerald (858 carats)
  • Mim emerald (1390 carats)



Category: Mineraloid

Colors: Multicolored, colorless

Hardness: 5.5 -6

Chemical Formula: SiO2·nH2O (Hydrated Silica – repeating unit)

Price: 30$ – 1,500$ per carat

Most Found: Australia, Ethiopia

Opal is the national gemstone of Australia. It is mostly found with sandstone, limonite, basalt and marl. The precious opal has the property of iridescence (play of color), meaning the stone changes color from different angles, while the common opal does not have it.

Opal was extremely rare and high in value, until the immense mines of it were found in Australia. In the middle ages, opal was considered the stone of luck, because of its multicolored appearance. This gem is known as the birthstone of October.

Some famous opal mineraloids in the world are:

  • The Olympic Australis (worth 2.5 million dollars)
  • The Queen’s opal
  • The flame queen opal
  • The galaxy opal
  • The Halley’s comet opal



Category: Silicate Mineral

Colors: Colorless (pure), blue, brown, orange, yellow, green, pink

Hardness: 8

Chemical Formula: Al2SiO4(F,OH)2

Price: 20$ per carat (blue, white), up to 1500$ per carat (yellow, orange)

Most Found: Utah (USA), Urals (Russia), Afghanistan, Brazil, Sri Lanka

The orange topaz is the traditional gemstone of the state of Utah, symbol of friendship and of birthstone of November. As of today, Brazil is the largest producer of this mineral. Sizes of some topaz stones mined Brazil can be the same as a boulder.

Topaz was associated with superstition among different cultures and in various eras. It was believed to cure mental illness in Britain, bring safety among Romans and in middle ages, to deflect the evil eye and enhance mental powers.



Category: Chalcedony (Quartz)

Colors: Brown

Hardness: 6.5 – 7

Chemical Formula: SiO2

Price: 20$ – 40$ per kilogram

Most Found: China, Brazil, Uruguay, the USA

Agate is one of the most used stones in hardstone carving. It is an ancient form of art, decoration and craft. It is a common mineral found mostly in volcanic rocks. The miners in China and India have reported getting respiratory diseases such as silicosis and tuberculosis.

Popular types of Agate are: Mexican, Turritella, Coldwater, Greek, Brazilian, Lace, Polyhedroid and Fire agate. This stone is associated with the month of September.



Category: Carbonate mineral (protein)

Colors: All colors

Hardness: 2.5 – 4.5

Chemical Formula: CaCO3

Price: 300$ – 1,500$

Most Found: China, Japan, Australia, Indonesia, Philippines

Gemstones are not always “stones”, in this case it is actually a byproduct of a living being. A pearl grows inside a shelled mollusk or a conulariids, two kinds of species that live in the ocean. The finest pearls are hard, round and smooth.

The primary reason for pearl harvesting is jewelry. Whether wild or cultured, hard or soft, all types of pearls are used in jewelry. A pearl is most often valued by its size and luster. This stone is associated with the month of June.

Here are some most famous pearls in the world:

  • Le Pelegrina pearl
  • Oriental pearl
  • Pearl Maxima
  • Pearl of Lao Tzu
  • Pearl of Kuwait
  • Pearl of Puerto



Category: Oxide mineral

Colors: Colorless, red, pink, blue, black, violet, dark green

Hardness: 7.5 – 8

Chemical Formula: MgAl2O4

Price: 200$ – 1000$ per carat

Most Found: Myanmar, Afghanistan, Sri Lanka, Australia


Spinel is the primary mineral of rare mafic igneous rocks. In the past, red spinels and rubies were unidentifiable, thus going under the same category as rubies. Now, they are known as spinel-rubies or balas rubies.

Today the largest spinel weighs 500 carats, known as Samarian spinel. This mineral is associated with the month of August.



Category: Oxide mineral

Colors: Green, grey

Hardness: 8 – 8.5

Chemical Formula: (Mg,Fe,Zn)2BeAl6O12

Price: 35,000$ per carat (average)

Most Found: Australia, Antarctica, Greenland

This gemstone was first discovered in Australia, in Musgrave ranges where it got its name from. It is a member of the taaffeite family of minerals, and one of the most rare and expensive stones. Although it is hard to price, jewelers value it around 35,000$.



Category: Zoisite mineral

Colors: Blue, violet, indigo

Hardness: 6.5

Chemical Formula: (Ca2Al3(SiO4)(Si2O7)O(OH)) + (Cr,Sr)

Price: 200$ – 500$ per carat

Most Found: Tanzania

Tanzanite is a rare gemstone of royal blue color, found in the east African country of Tanzania. It is a zoisite mineral (a calcium aluminum hydroxyl sorosilicate), that changes color when seen from different angles. Its indigo color comes from small amounts of vanadium.

It is slightly affordable than some of those other gemstones, and has great uses in jewelry. The biggest piece of this mineral is a nearly 17,000 carat stone. Tanzanite is associated with the month of December.



Category: Phosphate mineral

Colors: Turquoise, blue, blue-green

Hardness: 5 – 6

Chemical Formula: CuAl6(PO4)4(OH)8·4H2O

Price: 1$ – 10$ per carat

Most Found: Iran, Egypt, China, Mexico, Afghanistan

Turquoise is the hydrated phosphate of copper and aluminum. It has been known as a fine jewelry gemstone for thousands of years, but just like the other precious stones, it has also been a victim of counterfeit and devalued because of the same synthetic material.

Turquoise is the birthstone of Sagittarius. Its name comes from the French word “Turquois” meaning Turkish, because the stone first reached Europe from Turkey.

Turquoise has been associated as a stone of good fortune, with ancient cultures such as the Persians, Indus valley, Mesopotamia, ancient Egypt and even the Aztecs.



Category: Beryl mineral

Colors: Blue, cyan

Hardness: 7.5 – 8

Chemical Formula: Be₃Al₂SiO₆

Price: 100$ – 300$ per carat

Most Found: Sri Lanka, Brazil, Madagascar, USA

Aquamarine is Latin for seawater. Romans believed that this mineral would protect them in the ocean. The blue color of it comes from different charged atoms of ions. Deep colored aquamarine is called maxixe, and can be found in Madagascar.

The largest aquamarine stone was mined in Brazil, which weighs over 110 kilograms. This mineral is the birthstone of Pisces, and is associated with the month of March.



Category: Silicate mineral (Quartz)

Colors: Purple

Hardness: 7

Chemical Formula: SiO2

Price: 1$ – 10$ per carat

Most Found: Siberia, Sri Lanka, Brazil, Uruguay

Amethyst is one of the common semi-precious jewelry minerals, and is associated with the month of February. It obtains its purple/violet color from irradiation or impurities of iron ions. Amethyst has become cheap since the huge mines of it were discovered in Brazil.

The Greeks believed amethyst could prevent intoxication, and the Egyptians used it in jewelry long before. Medieval European soldiers wore amethyst amulets in battle for protection, as so beads of this mineral were found buried in anglo-saxon graves in England.



Category: Oxide mineral

Colors: Deep black, shades of red

Hardness: 6.5 – 7

Chemical Formula: SiO2

Price: 10$ – 500$ per carat

Most Found: Yemen, Uruguay, Argentina, Australia, Brazil

Commonly onyx is deep black colored with streaks of white in it, except for the sardonyx, another variant of this stone that comes in shades of red. It is unfortunate to say that most black onyx in the market nowadays are artificially colored.

Onyx has a long history of usage in jewelry, usually seen in men’s rings and beaded ornaments. Archaeologists have discovered pottery made of this stone in ancient Egypt.

It is believed that ancient Romans and Greeks entered battles wearing sardonyx stone talismans that had engravings of mars (god of war) on them.


Tiger’s Eye

Category: Chatoyant mineral

Colors: Golden, red-brown

Hardness: 5.5 – 6

Chemical Formula: SiO2

Price: Starts from 1$

Most Found: Australia, Burma, India, Namibia, South Africa

Chatoyancy is the feature of optical reflectance effect seen only in certain gemstones. Today, tiger’s eye is used in jewelry in most beaded bracelets, beaded necklaces and amulets. It is believed that this stone is good for fear and anxiety. Tiger’s eye is the birthstone of Gemini.



Category: Organic (fossilized tree resin)

Colors: Orange, yellow, honey

Hardness: 2 – 2.5

Chemical Formula: 80% Carbon, 10% Hydrogen, 10% Oxygen

Price: 10$ – 1,000$

Most Found: Poland, Russia

Amber is used in many decorative items, including jewelry ornaments such as amulets, beaded bracelets and necklaces. It is an ancient organic gemstone that has been appreciated for its color and exterior.

Historians have also reported its applications in medicine. Today, amber is burnt for its scent in most places of India and China. Amber is the birthstone of Taurus.



Category: Mineral (Jadeite and nephrite)

Colors: Shades of green, black, purple, yellow, white

Hardness: 6 – 7

Chemical Formula: NaAlSi₂O₆

Price: Up to 3,000$ per ounce

Most Found: China, Russia, Guatemala

French mineralogist Alexis Damour discovered that jade actually comes in two forms; jadeite and nephrite. While nephrite is a silicate of magnesium and calcium, jadeite is of sodium and aluminum, and the latter is more common. Jade is the birthstone of March.

This mineral was widely present in ancient and traditional China. It was used to make all types of ceremonial ornaments, from indoor objects, arts and jewelry to burial suits.

The biggest jade stone was discovered and mined in Myanmar, which weighs 175 tons and is worth 145 million dollars.



Category: Orthoclase mineral

Colors: Colorless, multiple colors

Hardness: 6

Chemical Formula: (Na,K)AlSi3O8

Price: 10$ – 500$ per carat

Most Found: Armenia, Australia, the Austrian Alps, Mexico, Madagascar

Moonstone has been used in jewelry for a long time. Amulets, beads and rings made of this mineral have become quite beautiful and admirable, and its natural glow is the reason behind it.

The Romans admired it and believed it was solidified from the rays of the moon. Moonstone is the state gemstone of Florida, despite not being naturally found there. It is also the birthstone of June.



Category: Nesosilicate mineral

Colors: Multicolored, blue (rare)

Hardness: 6.5 – 7.5

Chemical Formula (general): X3Y2(SiO4)3

Price: 500$ – 7,000$ per carat

Most Found: India, China, Australia, the USA

Garnet comes in almost all colors, but what makes it desirable in jewelry is the fiery red shades of it. In the USA, it is known as the state mineral of Connecticut and New York, and the birthstone of January.

Just like other precious and semi-precious gemstones, garnet too is used in earrings, rings, necklaces, amulets and beaded bracelets. It can be expensive, but not as expensive as ruby.

Since they both have almost the same color, people sometimes will buy garnet jewelry and show it off as ruby.



Final Words:

Even though this website is mostly designed to be about exotic metal jewelry, I believe Precious Stones and Gems are a huge part of the jewelry industry, because various gemstones add huge great value to these ornaments.

Gemstones have been believed to cure diseases, bring luck, victory and good fortune. Even today, they are used by many Chakra healers. Even though I don’t believe in those things, I can strongly agree that the beauty of pieces of jewelry is multiplied by adding certain gemstones in them.

Thanks again for reading. I hope you have found the article informative and helpful. If you believe particular information is false, drop a comment below and let me know of your opinion.






3 thoughts on “Precious Stones and Gems

  1. Very good review, I never seen a post anywhere else that had so much information on each different type of stone. I never thought rubies are more valuable than diamonds. I liked learning about topaz, since its my birthstone, but I have learned something I didn’t know thanks to this post, so thanks.

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