Blue Gemstones: 37 Varieties, Properties & Care Guide

Blue gemstones captivate us with their connection to sea and sky, representing one of nature's rarest colors. Today's gem market offers unprecedented quality and variety of blue stones. This comprehensive guide will help you understand what makes these gems special and how to select the perfect blue gemstone for your needs.

In this guide, you'll discover:

• How gemologists evaluate blue gemstone quality using specific color and clarity criteria that determine a stone's value and beauty.
• Which blue gemstones work best for everyday jewelry like rings versus those better suited for occasional wear or viewing collections.
• Detailed profiles of 37 different blue gemstones, from popular sapphires to rare specimens like jeremejevite and grandidierite.
• Special properties and treatments common to each blue gemstone variety that affect their appearance and value.
• Historical significance and symbolism associated with various blue gemstones that enhance their appeal beyond physical characteristics.

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How to Evaluate Blue Gemstone Quality: Essential Assessment Criteria

When selecting any blue gemstone, understanding how to assess quality helps you make informed decisions. Gemologists evaluate colored stones using several key factors.

What Determines Blue Gemstone Color Quality?

Gemologists assess color by examining three components: hue, tone, and saturation. Blue gemstones often display secondary hues alongside their primary blue color.

The most common secondary hues include:

• Green tints create greenish-blue stones like some aquamarines and paraíba tourmaline.
• Violet undertones appear in many sapphires, adding richness to their blue color.

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Generally, purer blue hues command higher values, though beautiful greenish and violetish blue gems remain highly sought after. Blue colors reach their maximum gamut limit (highest saturation) at medium-dark tones, around 85% on the tone scale.

Consider these color factors:

• Vivid saturation creates the most eye-catching, desirable blue gemstones.
• Overly dark stones appear inky or steely, obscuring their blue color.
• Very light blue stones may look washed out or grayish.

Beautiful blue gemstones come in various tones, from light sky blue to deep, rich navy, each appealing to different preferences.

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Why Clarity Requirements Differ for Blue Gemstones

Clarity standards for blue gemstones differ significantly from those for colorless diamonds. In blue stones, the color itself often masks inclusions, making them less noticeable.

Consider these clarity guidelines:

• Avoid stones with large inclusions or fractures that might compromise durability.
• Lighter blue gemstones benefit from better clarity grades since inclusions show more readily.
• Dark inclusions particularly detract from lighter blue stones' appearance.

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How to Choose Blue Gemstones for Different Jewelry Applications

If you're considering a blue gemstone for an engagement ring or fine jewelry, custom design offers superior results. CustomMade experts can help you select high-quality stones while avoiding common retail problems like this overly dark sapphire from James Allen.

Blue Gemstones Ideal for Everyday Wear

For rings worn daily, durability becomes crucial. The following blue gemstones rate at least 6.5 on the Mohs hardness scale, making them resistant to scratches. They also possess excellent toughness, reducing their likelihood of breaking when accidentally knocked against hard surfaces. With regular cleaning, these durable blue gems will maintain their beauty indefinitely.

Blue Sapphire: Unrivaled Color Saturation and Durability

Blue sapphire dominates the market for faceted blue gemstones, prized for its extraordinary color saturation. Royal engagement rings have further elevated its popularity. As the traditional September birthstone, sapphire belongs to the corundum mineral family—occurring in any color except red (which becomes ruby).

What makes sapphires special? The most remarkable reasons include:

• Their classic blue to violet hues develop from trace amounts of titanium and iron in their crystal structure.
• Most sapphires undergo heat treatment to enhance clarity and color.

Lab-created sapphires offer identical beauty and durability at lower prices.

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Blue Tourmaline (Indicolite and Paraíba): Rare Varieties with Electric Hues

A modern alternative for the October birthstone, tourmalines have recently surged in popularity and value. Tourmalines occur in every color, but blue specimens called indicolites remain rare and highly coveted.

Noteworthy aspects of blue tourmalines include:

• Their scarcity means indicolites often contain more inclusions than other tourmaline varieties.
• Iron traces create their distinctive blue color, sometimes enhanced through undetectable heat treatment.
• Copper-bearing varieties, first discovered in Brazil, became known as "paraíba tourmaline", though similar stones now come from other parts of the world.

Paraíba tourmalines display electric, neon-like blue-green colors and may receive clarity enhancement similar to emeralds.

Aquamarine: Quintessential Watery Blue Tones

Aquamarine captures watery blues and blue-greens but never reaches the dark tones or high saturation of sapphires. As the popular March birthstone, it traditionally served as a talisman to keep sailors safe at sea.

Important aquamarine characteristics include:

• Darker tones command higher values, even with slight grayness.
• Most aquamarines undergo heat treatment to reduce green hues for purer blue.
• Some specimens resist heat treatment, retaining their attractive sea-foam blue-green color.

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Spinel: Underrated Brilliance with Captivating Blue Hues

Often overlooked by consumers but beloved by gemologists, spinel has recently gained recognition as a modern August birthstone.

Blue spinels offer several advantages:

• They occur in various blue shades, with medium-toned, intensely saturated specimens being most desirable.
• Cobalt-colored spinels stand out for their bright, vivid blue hues.

Synthetic spinels, though common and inexpensive, frequently serve as simulants for other gemstones.

Turquoise: Ancient Blue Gem with Distinctive Appearance

Turquoise appears in everything from inexpensive costume jewelry to high-end designer pieces. Its hardness varies from 3 to 7.5, depending on the mineralogy of its host rock. As a traditional December birthstone with ancient symbolism, turquoise offers distinctive appeal.

Important considerations include:

• Only the highest-quality turquoise remains untreated; most undergoes stabilization to enhance color and durability.
• Reconstituted turquoise consists of ground turquoise powder mixed with other materials.

Watch for glass or plastic imitations sold as genuine turquoise.

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Blue Diamonds: Exceptional Rarity with Supreme Brilliance

Fancy-colored blue diamonds rank among the rarest gemstones, combining exceptional brilliance and dispersion with their unusual color.

Natural blue diamonds rarely reach high saturation, but treatment methods produce stronger colors:

• Irradiation and heat treatments enhance blue color.
• The HPHT process creates intense blue with minimal grayness.

Lab-created diamonds offer the blue diamond experience at lower costs.

This diamond has great color but contains many inclusions.  Fancy Intense Blue Diamond HPHT 3 carat Princess cut #31854 from R. Rothem Diamonds on Vimeo.  Licensed under CC By 3.0.

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Blue Chalcedony: Subtle Translucence with Affordable Beauty

Attractive translucence and affordability have sparked renewed interest in chalcedony.

Blue varieties include:

• Chrysocollachalcedony with gray or lavender undertones.
• A new variety called aquaprase™ displaying bright blue-green hues from nickel and chromium.

Lapidaries typically fashion these stones into cabochons or carvings to highlight their unique color and translucence.

Jeremejevite: Ultra-Rare Collector's Gem with Impressive Durability

One of the world's rarest minerals, jeremejevite occurs in just a few locations. Namibian specimens display light aquamarine-blue colors, while transparent crystals from other sources remain extremely uncommon.

Despite its rarity, jeremejevite offers excellent durability:

• It rates 6.5-7.5 in hardness.

It has no reported cleavage, reducing breakage risk.

Dumortierite: Distinctive Blue Mineral with Unique Formations

For unique cabochon options, dumortierite presents an excellent choice. This blue to violet-blue material usually occurs in massive form rather than facetable crystals. Particularly fascinating are specimens with dumortierite inclusions in quartz, creating structures resembling a coral reef.

Sapphirine: Rare Blue Mineral with Sapphire-Like Appearance

Named for its sapphire-like appearance, sapphirine ranges from light to dark blue or blue-green.

While fine facetable crystals remain rare collectors' items, this durable gem offers:

• Excellent 7.5 hardness rating.
• Poor cleavage, enhancing durability.
• Transparent specimens primarily from Sri Lanka.

Hawk's Eye: Mesmerizing Chatoyancy with Natural Blue Color

Hawk's Eye stones display enchanting chatoyancy (cat's-eye effect). These blue stones represent the precursor to golden tiger's eye before iron oxidation. Hawk's eye maintains the original titanium blue coloration for a mesmerizing optical effect.

Blue Jadeite: Ancient Treasured Material with Exceptional Toughness

Once treasured by ancient Mayans, blue jadeite occurs exclusively in Guatemala. Despite often appearing somewhat grayish, blue jadeite offers extraordinary toughness and fascinating musical qualities—when struck, jadeite rings like a bell!

Blue Gemstones for Occasional Wear

Not all blue gemstones withstand daily wear. Some have lower hardness ratings or tend to chip easily. These gems work best in earrings, pendants, and brooches. If used in rings, they require protective settings to minimize damage risk.

Tanzanite: Contemporary Blue-Violet Gem with Trichroic Properties

Found only in a small area of Tanzania, tanzanite has experienced skyrocketing popularity—even becoming a modern December birthstone.

Key tanzanite characteristics include:

• Intense blue-violet hues resulting from heat treatment.
• Lower price points compared to comparable sapphires.
• Tendency to chip if knocked against hard surfaces.

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Blue Moonstone: Ethereal Floating Adularescence Effect

The June birthstone option moonstone exhibits an unusual sheen called adularescence—often appearing as a blue cloud floating within a milky white stone.

Premium moonstones display:

• Bright, medium blue adularescence on a colorless body.
• High-domed cabochons that maximize the floating effect.

As a variety of feldspar, moonstone requires careful handling to avoid chipping and scratching.

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Iolite: Strong Pleochroism with Affordable Pricing

Though never reaching fine sapphire's color saturation, iolite offers excellent value with no known treatments.

Gemologists consider it underappreciated for several reasons:

• Strong pleochroism creates fascinating color shifts from dark blue to light yellow depending on viewing angle.
• Historical significance as the possible "Viking Sunstone," used for ocean navigation.
• Perfect cleavage in one direction creates breakage risk if improperly handled.

Iolite is often confused with tanzanite.

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Blue Apatite: Electric Color with Moderate Hardness

The apatite mineral group encompasses several varieties, but gemologists often use "apatite" when referring to gemstone varieties regardless of specific composition.

Apatite gems offer distinctive features:

• Brazilian specimens display spectacular neon blue-green colors.
• At 5 on the Mohs scale, apatites require careful handling.

Heat sensitivity prevents cleaning with mechanical or heated cleaning systems.

Larimar: Unique Caribbean Blue with Distinctive Patterns

In the Dominican Republic, fibrous pectolite forms dense blue material known as larimar.

This unique gem offers:

• Caribbean sea-blue coloration found nowhere else on Earth.
• 6-6.5 hardness providing moderate scratch resistance.
• A distinctive souvenir opportunity for collectors and travelers.

Benitoite: Extreme Dispersion Exceeding Diamond

For those seeking extraordinary optical properties, benitoite delivers remarkable performance.

This rare California gemstone features:

• Greater dispersion (fire) than diamond.
• Deep blue coloration with exceptional brilliance.
• Lower price than blue diamonds despite extreme rarity.
• Hardness of 6-6.5 requiring protective settings.

Blue Zircon: Exceptional Brilliance with Affordable Pricing

Often overlooked and confused with cubic zirconia, natural zircon possesses dazzling brilliance and fire.

As a modern December birthstone, blue zircon offers several advantages:

• Bright blue hues often with greenish undertones.
• Exceptional sparkle that rivals diamond.
• Affordable pricing despite impressive optical properties.
• Brittleness requiring protective settings.

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Lapis Lazuli: Ancient Royal Blue with Historical Significance

With symbolism thousands of years old, lapis lazuli represents one of the most culturally significant blue gemstones.

As one of the traditional birthstones for December, lapis offers:

• Bold royal blue coloration.
• Relative toughness despite moderate hardness (5-6).

Regional preference variations—most markets prefer solid blue, while American collectors often appreciate a smattering of pyrite inclusions.

Blue Topaz: Affordable Brilliance with Treatment-Enhanced Color

This November birthstone is best known for reddish and yellow hues, but the advent of irradiation and heat treatment has given rise to inexpensive and attractive blue topaz stones. Treatment produces stable colors in gems that remain perfectly safe for wear. While topaz is somewhat prone to chipping, proper cutting angles should reduce this risk.

Blue Opal: Oceanic Play-of-Color with Special Care Requirements

In a class of its own, opal serves as the traditional October birthstone with a rich folklore. Blue precious opals display play of color resembling sunlight dancing on ocean surfaces.

Important opal considerations include:

• Softness (5.5-6.5) making them prone to scratching.
• Some opals may craze (develop internal cracks) if they dry out.
• Triplet construction can protect opals with hard cap materials.

Need for proper care to maintain beauty.

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Lazulite: Deep Blue Stone with Challenging Lapidary Properties

Though faceted lazulites remain extremely rare and too brittle for jewelry, cabochons from massive material offer greater stability. Often confused with other blue stones, lazulite presents challenges in both identification and cutting but rewards with attractive blue coloration.

Grandidierite: Extremely Rare Blue-Green with Collector Appeal

Grandidierite above 2 carats in gem quality ranks among the world's rarest gemstones. A 2016 find in Madagascar has increased availability of transparent material.

This blue-green stone offers:

• Excellent scratch resistance (7-7.5 hardness).
• Brittleness requiring careful setting and handling.
• Exceptionally high value due to extreme rarity.

Blue Akoya Pearls: Naturally Tinted Oceanic Treasures

When people think of pearls (the June birthstone), they typically envision white or cream colors.

Recently, blue Akoya pearls have captivated collectors with:

• Blue tint combined with the desirable luster of white Akoya pearls.
• Greater rarity than traditional white pearls.
• History of rejection by pearl farmers before becoming fashionable.

Like all pearl varieties, blue Akoyas require special care to maintain their beauty.

Azurite: Bold Copper Mineral with Rich Blue Coloration

Bold blue colors make azurite popular among collectors and jewelry enthusiasts. Often confused with lapis lazuli, azurite frequently forms with green malachite, allowing lapidaries to create striking blue-green cabochons. Crystalline material suitable for faceting remains rare, with larger cut stones appearing too dark for optimal color display.

Kyanite: Variable Hardness with Directional Properties

Kyanite presents a mineralogical curiosity with hardness varying from 4 to 7.5 depending on the crystal axis. Usually appearing somewhat grayish-blue with inclusions, kyanite nevertheless attracts interest from lapidaries who manage to overcome its challenging cleavage and brittleness to create faceted specimens.

Labradorite: Spectacular Blue Flash with Striking Optical Effects

Certain labradorite specimens display remarkable blue sheen when properly oriented. This phenomenon, called labradorescence, results from twinned mineral planes within the crystal structure. When this blue flash covers the entire stone, the visual impact proves spectacular, especially given labradorite's affordability and relative abundance.

Sodalite: Accessible Deep Blue with Moderate Durability

Sodalite provides another opaque blue option for jewelry. As a component of lapis lazuli, sodalite has historical significance while remaining affordable even in large sizes. Lapidaries frequently use this material for carvings, cabochons, and beads. With 5.5-6 hardness, sodalite may scratch over time but seldom breaks.

Sillimanite: Pale Blue Variety with Challenging Lapidary Properties

Sometimes called fibrolite due to its occasionally fibrous structure, sillimanite can form beautiful crystals. Despite good hardness (6.5-7.5), its brittleness and perfect cleavage make it challenging for lapidaries and risky for jewelry. While most commonly occurring in pale yellow, sillimanite occasionally displays light blue hues resembling pale aquamarine. Be aware that most dark blue specimens have undergone dye treatment.

Shattuckite: Turquoise-Like Color with Distinctive Formation Patterns

First discovered in Arizona's Shattuck Mine, shattuckite often exhibits colors similar to turquoise. This copper silicate rarely forms large crystals; instead, it frequently pseudomorphs (replaces while maintaining the original form) after malachite. When mixed with quartz in massive deposits, shattuckite gains sufficient durability for jewelry applications while maintaining its attractive blue and blue-green colors.

Blue Collector's Gemstones

Some gems are best for display only, safe from the bumps and scratches that can arise from jewelry wear. Although these blue gemstones may not be ideal for jewelry, they can bring color and interest to a viewing collection.

Smithsonite: Exceptional Optical Properties with Delicate Structure

Made of zinc carbonate, smithsonite combines brittleness with softness (4-4.5 hardness) yet delivers exceptional optical properties. Faceted specimens exhibit outstanding dispersion (fire), making them highly desirable for serious collectors. Blue to blue-green material ranks among the most sought-after colors.

Vivianite: Fascinating Color-Changing Properties with Extreme Softness

Vivianite presents a fascinating mineralogical oddity—it's extremely soft (1.5-2 hardness) and darkens upon light exposure. Most specimens emerge from the ground colorless or pale green, darkening to deep blue over time with light exposure. Despite these challenges, skilled lapidaries occasionally succeed in faceting this unusual material.

Blue Halite: Natural Cubic Crystals with Water-Soluble Properties

Perhaps the most edible gemstone, halite (sodium chloride/table salt) develops spectacular royal blue and violet colors due to crystal lattice defects. Collectors prize perfect cubic crystals, but halite's perfect three-directional cleavage, solubility in water, brittleness, and low hardness make it impractical for lapidary work.

Hemimorphite: Delicate Blue Crystal Clusters with Collector Appeal

This zinc silicate mineral displays pale to rich blue colors. While hemimorphite rarely forms large crystals, lapidaries occasionally create cabochons from massive material. Some microcrystalline specimens attract mineral collectors, and a few facetable crystals have emerged from mines. However, hemimorphite's brittleness and 4.5-5 hardness make it too fragile for jewelry wear.

Scorodite: Hazardous Composition with Striking Blue Coloration

This iron arsenate mineral combines softness (3.5-4) with brittleness, making it unsuitable for jewelry. More concerning, scorodite's arsenic content poses potential health risks—contact with water (including perspiration) could facilitate arsenic leaching. Facetable crystals exist, though rarely, and lapidaries willing to take precautions can showcase this mineral's blue colors in cut specimens for display collections only.

Cavansite: Distinctive Blue Crystal Clusters

Most often found in Pune, India, cavansite crystals can have a beautiful blue hue. However, specimens large and transparent enough to facet are extremely rare. Sometimes druzy or massive cavansite is worn as jewelry. However, these stones are soft and brittle.

Frequently Asked Questions About Blue Gemstones

What makes blue such a rare color in gemstones?

Blue is one of nature's rarest colors in gemstones because it typically requires specific trace elements like titanium, iron, copper, or cobalt within the crystal structure. These elements must be present in precise amounts and conditions during formation to create the blue color, making naturally occurring blue gemstones relatively uncommon compared to other colors.

Which blue gemstones are best for everyday wear in rings?

For everyday ring wear, choose blue gemstones with at least 6.5 hardness and good toughness, such as blue sapphire, blue tourmaline (including paraíba varieties), aquamarine, blue spinel, and blue diamonds. These stones resist scratching and are less likely to break when accidentally knocked against hard surfaces.

How do gemologists evaluate the quality of blue gemstones?

Gemologists evaluate blue gemstones based on three color components: hue (the actual color, including secondary colors like greenish or violetish blue), tone (how light or dark the color is), and saturation (how vivid or intense the color appears). They also assess clarity differently than for diamonds, as color often masks inclusions in blue stones. Generally, purer blue hues with vivid saturation at medium-dark tones (around 85%) are most valuable.

Are most blue gemstones treated to enhance their color?

Yes, many blue gemstones undergo treatment to enhance their color or clarity. Common treatments include heat treatment for sapphires and aquamarines, irradiation for blue topaz, and stabilization for turquoise. Paraíba tourmalines may receive clarity enhancements similar to emeralds. Natural, untreated blue gemstones with vivid color often command premium prices.

What's the difference between blue sapphire and tanzanite?

Blue sapphire and tanzanite differ in several ways: sapphire is much harder (9 vs. 6-7), making it more durable for everyday wear; sapphire displays blue to violet-blue hues from titanium and iron, while tanzanite shows distinctive blue-purple coloration; tanzanite is found only in Tanzania while sapphires come from multiple locations worldwide; and tanzanite is generally more affordable than comparable quality sapphires despite being rarer in nature.

Which blue gemstones are the rarest?

The rarest blue gemstones include jeremejevite, grandidierite, benitoite, paraíba tourmaline, and natural blue diamonds. These gems are found in very limited locations worldwide and rarely occur in sizes suitable for jewelry. Their extreme scarcity makes them highly valuable collector's items, with prices often reflecting their rarity rather than their practical wearability.

Can you recommend affordable alternatives to blue sapphire?

Excellent affordable alternatives to blue sapphire include blue topaz (the most budget-friendly option), iolite (with fascinating pleochroism), blue zircon (with diamond-like sparkle), blue spinel, and blue tourmaline varieties other than paraíba. These stones offer attractive blue colors at significantly lower price points than fine blue sapphires.

How should I care for my blue gemstone jewelry?

Care requirements vary by stone type. Generally, harder stones like sapphire and spinel can be cleaned with mild soap and water or ultrasonic cleaners. More delicate stones like tanzanite, opals, and pearls require gentle cleaning with a soft cloth and mild soap. Avoid exposing any gemstones to harsh chemicals, extreme temperature changes, or prolonged sunlight. Store them separately to prevent scratching, and have jewelry with valuable stones checked by a professional jeweler annually.

What causes the special optical effects in some blue gemstones?

Special optical effects in blue gemstones result from their unique structural properties: adularescence (blue floating effect in moonstone) comes from light scattering between thin layers; chatoyancy (cat's eye effect in hawk's eye) results from parallel fibrous inclusions; labradorescence (blue flash in labradorite) is caused by light interference from twinned crystal planes; and play of color in blue opal comes from diffraction of light through microscopic silica spheres of uniform size.

Are lab-created blue gemstones identical to natural ones?

Lab-created blue gemstones have the same chemical composition, crystal structure, and physical properties as their natural counterparts. They display identical hardness, color, and optical characteristics. The main differences are origin (laboratory vs. earth), price (typically 30-40% less), and sometimes subtle growth pattern differences visible only under microscopic examination. Lab-created sapphires and blue diamonds offer excellent quality and value while being ethically sourced and environmentally sustainable alternatives.