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11 Beautiful Blue Gemstones You Need to See

Posted by Melody Douglas | Feb 5, 2021 4:19:00 PM

Miscellaneous

 

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Out of all the rainbow of colors gemstones can come in, blue gemstones are the most popular. There are a huge variety of blue gems, from delicate pale aqua to richly saturated dark blue. Some stones are pure blue, while others include shades of violet, green, white, or gold.

This guide explores 11 of the most popular and beautiful gemstones. Each of these blue gemstones includes a chart with important characteristics, as well as average prices for each gemstone, how it is used in jewelry, and how it's unique from other blue gemstones.

If you are interested in purchasing a blue gemstone or jewelry that includes a blue gemstone but aren't sure which type of stone to buy, our guide will help you easily compare different blue stones. At the end of this guide, there is also a section on how to choose the best blue gemstone for you.

 

The Blue Gemstones

Agate

Aquamarine

Azurite

Benitoite

Blue Diamond

Lapis Lazuli

Sapphire

Tanzanite

Blue Topaz

Tourmaline

Turquoise

 

6 Key Gemstone Terms, Defined

Before jumping into the different blue stones, let's clarify some of the key criteria used to assess gemstones.

 

Criteria 1: Diaphaneity

Also known as transparency, diaphaneity describes how light interacts with the surface of a material. There are three types of interactions.

  • Transparent: Light can enter and exit the material (such as glass).
  • Translucent: Light can enter and exit, but it gets distorted passing through the material (such as parchment paper).
  • Opaque: Light cannot penetrate the surface (such as wood).

 

Criteria 2: Hardness

The harder a gemstone is, the less susceptible it is to damage.The Mohs scale measures mineral hardness on a scale of 1-10. Gemstones with a hardness of about 7.0 or less are often not recommended to be worn daily because of the high possibility of them getting scratched or otherwise damaged.

 

Criteria 3: Specific Gravity

Specific gravity measures the relative density of a gemstone. A one carat gemstone with a higher specific gravity will be slightly smaller than a one carat gemstone with a lower specific gravity.

 

Criteria 4: Refractive Index

Refractive index measures how light passes through a material. Gemstones with a higher refractive index appear more brilliant and “sparkly” than those with lower refractive indexes. Most gemstones have refractive indexes between 1.5 and 1.7. A refractive index above 2.0 is rare and seen only in a handful of gemstones.

 

Criteria 5: Luster

Luster refers to how a gemstone appears when light hits it. There are multiple categories of luster. The ones mentioned in this guide are:

  • Adamantine: Mirror-like appearance; highest degree of luster
  • Dull: Reflects little light, but can be enhanced by polishing
  • Resinous: Appearance of resin or plastic
  • Vitreous: Glass-like
  • Waxy: Resembles wax

 

Criteria 6: Price per Carat

A carat refers to 20mg of a stone. For each gemstone, average price can vary widely depending on the quality and cut of the gem, but rough averages are given so you can get a sense of how expensive one stone is compared to the others. Price is based on cut and polished gems, not rough gems.

 

Agate

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Color Range

All shades of blue, often with other colors included

Diaphaneity

Translucent

Mohs Scale Hardness

6.5-7

Specific Gravity

2.66

Refractive Index

1.53-1.54

Luster

Waxy

Average Price per Carat

$0.50-$25

 

Agate, a banded form of the mineral chalcedony, comes in a variety of a variety of vivid colors, including the full spectrum of blue. These colors can be either natural or enhanced with dyes. Because of the potential variation in banding and color, agate has some of the widest variation from one stone to another seen in any mineral. You could purchase ten pieces of agate, and they could all look completely different from one another.

Agate is also one of the cheapest gemstones on this list, and agate jewelry is often very reasonably priced. It is most common for agate stones to be used as pendants for necklaces since large pendants include more bands of color than smaller pieces of agate would.

Where it’s found: Agate is very abundant and found all over the world.

What sets it apart: Its vivid bands often comprising a variety of colors.

 

Aquamarine

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Color Range

Very light to dark blue, often with greenish hues

Diaphaneity

Transparent to translucent

Mohs Scale Hardness

7.0-8.0

Specific Gravity

2.72

Refractive Index

1.57-1.58

Luster

Vitreous to resinous

Average Price per Carat

$10-$500

 

Aquamarine prices can vary widely depending on the size and quality of the stone. As with most blue gemstones, stones that are a darker, more vivid blue are generally more expensive (and rarer) than light blue stones.

Aquamarine is a popular gemstone and is used in many types of jewelry, although rings are often the most popular way for them to be set. Aquamarine is also the birthstone for the month of March, which helps contribute to its popularity. Aquamarine is often found in large crystals which makes it possible for large stones to be cut, polished, and set into jewelry or purchased by collectors. The largest gem-quality aquamarine ever discovered weighed over 240 pounds.

Where it’s found: Most aquamarine is mined in Brazil, with other large deposits found in Asia, Africa, and the Middle East.

What sets it apart: Aquamarine stones are often highly transparent, causing them to catch a lot of light and sparkle more than other stones.

 

Azurite

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Color Range

Deep blue

Diaphaneity

Transparent to Translucent

Mohs Scale Hardness

3.5-4.0

Specific Gravity

3.7-3.8

Refractive Index

1.73-1.84

Luster

Vitreous or dull

Average Price per Carat

$10-$100

 

Azurite is known for its deep blue, azure color. As opposed to many other blue gemstones, azurite rarely needs to undergo treatment to enhance its color. Due to its vivid color, azurite has been used as a pigment for hundreds of years.

As opposed to many other blue gemstones, azurite is not faceted. Instead, it is cut and polished into pieces known as cabochons. When put in jewelry, azurite is often combined with deep green malachite. The two minerals are often found in the same deposit.

As one of the softer stones, azurite jewelry must be handled with care, or the stones must be placed in settings that protect them from bumps and scrapes. Over time, azurite’s deep blue color can fade to green; all azurite jewelry should be safely stored away from sunlight and drafts, preferably in a closed jewelry box.

Where it’s found: Azurite is one of the rarer blue stones, but significant deposits have been found in the USA, France, and Namibia.

What sets it apart: Its deep azure color.

 

Benitoite

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Color Range

Medium to dark blue or violet

Diaphaneity

Transparent to Translucent

Mohs Scale Hardness

6.0-6.5

Specific Gravity

3.64

Refractive Index

1.76-1.80

Luster

Vitreous

Average Price per Carat

$250-$5000

 

Benitoite is one of the world’s rarest gemstones, found in just one place in the world. Benitoite has one of the highest dispersion ratings of all gemstones, including diamond. Dispersion rating measures the ability to take white light and disperse it to other colors of the spectrum. This gives benitoite its characteristic brilliance and fire.

When used in jewelry, benitoite stones tend to be small due to both their high price and the rarity of the gemstone.

Where it’s found: San Benito County, California

What sets it apart: Its rarity and natural “fire”.

  

Blue Diamond

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Color Range

Pale to dark blue

Diaphaneity

Transparent

Mohs Scale Hardness

10.0

Specific Gravity

3.52

Refractive Index

2.42

Luster

Adamantine

Average Price per Carat

Treated: $1,500-$11,500

Naturally Colored: $10,000 -$100,000+

 

Diamond is most famous as a colorless stone, but blue diamonds can be created by treating clear diamonds. Also, deposits of naturally blue diamonds have been found, but they are very rare. Blue diamonds often have a light blue color, often with a greenish tint.

Diamond is the hardest natural material on earth, and it also has one of the highest refractive indexes of all gemstones. Blue diamonds are nearly impossible to damage and can therefore be used in all types of jewelry.

Diamonds are one of the most expensive gemstones, and blue diamonds can command even higher prices than regular diamonds because of their rarity and the treatment required to enhance their color. Naturally blue diamonds, because they are so rare, are significantly pricier than comparable colorless diamonds.

Where it’s found: Diamonds are found worldwide, with large mines in Russia, Western Australia, and Southern Africa.

What sets it apart: Its hardness, high refractive index, and brilliant adamantine luster.

 

Lapis Lazuli

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Color Range

Medium-deep blue, often with white and gold mottling

Diaphaneity

Semi-translucent to opaque

Mohs Scale Hardness

5.0-5.5

Specific Gravity

2.75

Refractive Index

1.50

Luster

Dull

Average Price per Carat

$1-$50

 

In contrast to the other gemstones on this list, lapis lazuli is not a mineral. Instead, it’s a rock composed of multiple minerals including lazurite, calcite, and sparkling pyrite flecks. Since antiquity, lapis lazuli has been used for jewelry and as a dye. On the famous funeral mask of Tutankhamun, the eyebrows were made of lapis lazuli.

Lapis lazuli stones are often cut into cabochons and beads to be used in bracelets, necklaces, and pendants. Some pieces are also ornately carved and then used in jewelry.

Where it’s found: Lapis lazuli is found in numerous countries, but Afghanistan is the world’s leading source of the stone.

What sets it apart: The contrast between the deep blue stone and sparkling golden flecks often found in lapis lazuli.

 

Sapphire

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Color Range

Deep blue, occasionally clear and light blue

Diaphaneity

Transparent to opaque

Mohs Scale Hardness

9.0

Specific Gravity

4.00

Refractive Index

1.76-1.77

Luster

Vitreous to adamantine

Average Price per Carat

$500-$5000

 

Sapphire is the world’s most popular blue gemstone, beloved for its deep blue color and resistance to damage. They are also one of the moore expensive gemstones on this list. Sapphires with a more vivid, saturated blue color are more expensive than paler stones, and heat treatment is sometimes used to enhance the color of a sapphire. Sapphires that have deeply saturated color without any heat treament are significantly more expensive than sapphires that have undergone heat treatment.

Sapphires are widely used in all types jewelry, and, because of their durability, wearers do not have to worry about damaging the stone. Sapphire stones also often have high clarity and a brilliant cut, enhancing their sparkle.

One of the most famous pieces of sapphire jewelry is the engagement ring of Diana, Princess of Wales, now worn by Kate Middleton. The ring features a 12-carat sapphire surrounded by diamonds.

Where it’s found: Sapphires are found throughout the world. The three most famous countries for sapphire mining are Sri Lanka, Myanmar, and Pakistan.

What sets it apart: Its durability and brilliance.

 

Tanzanite

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Color Range

Pale to dark blue, violet

Diaphaneity

Transparent

Mohs Scale Hardness

6.5

Specific Gravity

3.30

Refractive Index

1.69-1.70

Luster

Vitreous

Average Price per Carat

$75-$1500

 

Tanzanite is one of the most newly-discovered gemstones; the single deposit was only discovered in 1967. Since then, however; tanzanite has achieved widespread popularity due to its deep blue and violet coloring. Deep blue and bluish violet tanzanite stones are the most desired (and expensive) form of the stone, but tanzanite can also come in pale hues. Most tanzanite undergoes heat treatment to deepen its blue color.

Tanzanite is often used as a less expensive alternative to similarly-colored sapphire. However, tanzanite’s low degree of hardness makes it susceptible to damage, so it is often set in pendants and earrings, which are prone to fewer bumps than bracelets and rings.

Tanzanite is one of the rarer gems, and some people expect deposits to run out in several decades. Because of this, tanzanite prices are expected to rise in the future.

Where it’s found: Tanzanite is found at a single site, in the northern hills of Tanzania.

What sets it apart: One of the most affordable deep-blue gemstones.

 

Blue Topaz

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Color Range

Pale to dark blue, also comes in other colors

Diaphaneity

Translucent to transparent

Mohs Scale Hardness

8.0

Specific Gravity

3.53

Refractive Index

1.62-1.64

Luster

Vitreous

Average Price per Carat

$5-$25

 

Topaz has one of the widest color ranges of any gemstone, with blue being one of the most common colors. Topaz’s blue color rarely occurs naturally; the stone is almost always treated to turn it blue or deepen its blue color. Additionally, topaz is pleochroic, meaning it can appear different colors depending on the direction you’re looking at it.

Topaz forms some of the largest crystals of any gemstone. Brazilian deposits are particularly large, and topaz crystals have been discovered that weigh over 500 pounds and are the size of boulders.

Topaz is one of the least expensive blue gemstones and this, coupled with its naturally large crystals, make it possible for large topaz stones to be set in jewelry at affordable prices. After topaz has been faceted, it can take such a high polish that the stone is slippery to the touch.

Where it’s found: Topaz is an abundant gemstone and found in numerous countries. Significant deposits are in Brazil, Utah, and the Ural Mountains of Russia.

What sets it apart: Low price and high polish.

 

Tourmaline

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Color Range

Light to dark blue, as well as violet-blue and greenish-blue

Diaphaneity

Transparent to opaque

Mohs Scale Hardness

7.0-7.5

Specific Gravity

3.06

Refractive Index

1.62-1.64

Luster

Vitreous

Average Price per Carat

Paraíba: $150-$16,000

Other varieties: $5-$500

 

Tourmaline has one of the widest color ranges of any gemstone, and blue tourmaline can range from pale aqua to deep azure and nearly every hue in between. The most famous variety of blue tourmaline is Paraíba Tourmaline (pictured above), which can come in vivid shades of blue, violet-blue, or greenish-blue not found naturally in other tourmaline stones. Paraíba Tourmaline is very rare, so its prices are much higher than other varieties of tourmaline. On rare occasions, blue tourmaline also includes a cat’s eye, where light reflects off the stone in a way that resembles the slit eye of a cat.

Tourmaline is used in a wide variety of jewelry, and blue tourmaline stones are often set with tourmaline of other colors for contrast and variety.

Where it’s found: Paraíba Tourmaline is found in Paraíba, Brazil, and other forms of blue tourmaline are found in multiple sites around the world.

What sets it apart: Its wide range of colors that cover nearly the entire blue spectrum.

 

Turquoise

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Color Range

Light-medium blue and blue-green

Diaphaneity

Opaque

Mohs Scale Hardness

5.0-6.0

Specific Gravity

1.61-1.65

Refractive Index

2.73

Luster

Waxy to subvitreous

Average Price per Carat

$5-$500

 

One of the oldest stones used for jewelry, turquoise has long been prized for its vivid sky blue and blue-green color, often highlighted by an attractive spiderweb of dark veins across the stone.

Turquoise doesn’t have the sparkle and clarity of many other blue stones, but its rich color has kept it popular for centuries. When used in jewelry, turquoise is often formed into cabochons or beads. Because it’s a relatively soft stone, it can also be intricately carved for pendants and other jewelry pieces.

Where it’s found: There are significant deposits in the Middle East, USA, and China.

What sets it apart: Its opaque blue-green color.

 

How to Pick the Perfect Blue Gemstone

Each of the blue stones above has attractive and unique characteristics, but which one is best for you? There are four criteria to consider when choosing a gemstone:

 

Price

This will likely be the most important factor in picking a blue gem. You may love sapphires but don't want to spend several thousand dollars on a high-quality piece of sapphire jewelry. 

Browse the price ranges listed for each of the blue stones, keeping in mind that price can vary significantly depending on the size, cut, and quality of a stone. Also, if you're interested in a specific stone that's out of your price range, there are often less expensive but similar-looking alternatives. Tanzanite is often used as a substitute for sapphire, and many aquamarines have a light blue color similar to blue diamonds.

If you have your heart set on a specific gemstone, you may be able to find a price within your budget by looking at smaller stones or stones with minor blemishes or discolorations (these are often very difficult or impossible to see with the naked eye). A jeweler can explain the finer points of gemstone pricing if you want more information.

 

Color

Blue gemstones come in a wide range of colors, from pale aquas to rich dark blues. Even if you think you already know the colors a particular gemstone comes in, take a look at the color ranges listed above. Many gemstones come in a wider range of colors than you might have expected. Sapphires, for example, are famous for their velvety blue color, but they can also occur in lighter shades of blue. You may be interested in a pure blue stone or a blue gemstone with shades of other colors, such as green or violet.

 

Hardness

A gemstone's hardness is another important factor to think about. You should not purchase a piece of jewelry with a gemstone that has a hardness of less than 7.0 if you plan on wearing the jewelry daily because the stone could become scratched or cracked. (An exception is if the stone has been placed in a special setting to protect it from damage.)

So, for jewelry like bracelets and rings, that often get bumped, choose a stone with a higher hardness, like sapphire or blue topaz, or only wear the jewelry on special occasions. Softer stones set into earrings or necklaces can be worn more frequently, but you should still be careful to avoid damaging them.

 

Jewelry Types

Some gemstones are frequently used in the same types of jewelry. Agate, for example, is often used in necklace pendants, while sapphire's brilliant sparkle and high price mean a single stone is often set into a ring. If you're looking for a particular type of jewelry, you may want to choose a gemstone that's often used for those pieces. 

 

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