Aquamarine: The Gemstone of the Sea

Aquamarine, a name that evokes images of crystal-clear tropical waters, is a beloved gemstone cherished for its stunning blue to blue-green hues. Belonging to the beryl family, the same mineral group as emerald and morganite, aquamarine offers a beautiful and durable option for fine jewelry. Its serene colors and good hardness make it a popular choice for rings, necklaces, earrings, and bracelets.

Definition

Aquamarine is a precious gemstone, a variety of the mineral beryl. Its chemical composition is beryllium aluminum cyclosilicate (Be3Al2(SiO3)6). The name 'aquamarine' is derived from the Latin words 'aqua marina', meaning 'water of the sea', a direct reference to its characteristic colors.

Key Features

• Color: The most desirable colors range from a deep, vibrant blue to a greenish-blue. Lighter, pastel shades are also common and popular. The intensity and purity of the color are significant value factors.
• Clarity: Like most gemstones, aquamarine is typically eye-clean, meaning it has no visible inclusions to the naked eye. Minor inclusions are acceptable if they do not detract from the overall beauty.
• Hardness: Aquamarine ranks 7.5 to 8 on the Mohs scale of hardness, making it sufficiently durable for everyday wear in most types of jewelry.
• Luster: It exhibits a vitreous (glassy) luster, which enhances its brilliance and beauty when cut and polished.
• Specific Gravity: Approximately 2.68 - 2.80.
• Refractive Index: Around 1.577 - 1.583.

Origin and History

Aquamarine has been known and treasured since ancient times. Roman naturalist Pliny the Elder described the gem in the 1st century AD, noting its resemblance to the sea. It was believed to possess properties that calmed storms and ensured the safety of sailors at sea, making it a protective amulet for mariners.

Historically, significant sources were found in Russia, particularly in the Ural Mountains, during the 18th and 19th centuries. More recently, Brazil became a major supplier of high-quality aquamarine. Other notable sources include Madagascar, Nigeria, Mozambique, Zambia, Tanzania, Kenya, and parts of the United States.

Types / Variations

While aquamarine itself is a variety of beryl, the primary variation lies in its color. The distinct blue and blue-green shades are attributed to trace amounts of iron within the crystal structure. The depth of color can vary significantly:

• Pala-type Aquamarine: This refers to stones with a pure, deep blue color, often found in the Minas Gerais region of Brazil.
• Brazilian Aquamarine: Typically exhibits a lighter, sky-blue hue.
• Greenish-Blue Aquamarine: Some stones have a more pronounced green tint, which can be appealing to certain tastes.

It is important to note that while some aquamarines exhibit a rich blue color naturally, very pale stones are sometimes heat-treated to enhance their color. This is a common and accepted practice in the industry.

How It's Made

Aquamarine is a naturally occurring gemstone formed deep within the Earth's crust under specific geological conditions involving heat, pressure, and the presence of beryllium and aluminum. These crystals grow within pegmatite formations, which are coarse-grained igneous rocks.

The rough crystals are mined from these deposits. Once extracted, they are meticulously cut and polished by lapidaries to reveal their beauty and maximize their brilliance. The faceting of the gemstone is crucial to its sparkle and overall appearance. Common cuts include oval, emerald, round, pear, and cushion shapes. Emerald cuts are particularly popular as they showcase the stone's clarity and color without excessive light dispersion.

Grading & Quality Standards

Like other precious gemstones, aquamarine quality is assessed based on the familiar 4 Cs, though color is often the most dominant factor:

• Color: The most important factor. Deeper, more saturated blues and blue-greens are generally more valuable. A pure, intense blue is highly sought after.
• Clarity: Aquamarine is usually eye-clean. The fewer inclusions visible to the naked eye, the higher the quality and value.
• Cut: A well-executed cut will maximize the stone's brilliance, bring out its best color, and ensure durability. Symmetry and polish are key.
• Carat Weight: Larger stones are rarer, especially those with exceptional color and clarity, so value increases significantly with size.

Buying Guide

When purchasing aquamarine jewelry, consider the following:

• Color Preference: Decide whether you prefer a deep ocean blue, a vibrant sky blue, or a greenish-blue hue.
• Size and Shape: Consider the overall design of the jewelry and how the stone's size and shape will fit. Emerald cuts and oval cuts are popular choices.
• Setting: Aquamarine's hardness makes it suitable for most settings. Yellow gold can provide a beautiful contrast to blue stones, while white gold or platinum offer a cool, modern look. Bezel settings offer excellent protection for the gemstone.
• Clarity: Look for stones that appear clean to the naked eye.
• Certification: For significant purchases, consider requesting a gemological laboratory report from a reputable lab, which verifies the stone's identity and quality characteristics.
• Source: While specific geographic origins can influence price, focus primarily on the beauty and quality of the individual stone.

Price Range & Value Factors

Aquamarine prices vary widely based on the 4 Cs, with color being the primary driver. Stones with a rich, saturated blue color, excellent clarity, a precise cut, and larger carat weights command the highest prices.

Generally, aquamarine is more affordable than diamonds, sapphires, or emeralds. However, exceptional stones can still be quite valuable. Pale blue or heavily included stones will be at the lower end of the price spectrum, while deep blue, eye-clean stones over 5 carats can be significantly more expensive.

The market price is also influenced by treatments. Untreated stones with desirable colors are typically more valuable than those that have been heat-treated to improve their color saturation.

Care and Maintenance

Aquamarine is relatively durable but requires proper care to maintain its luster and prevent damage:

• Cleaning: Clean with warm water, mild soap, and a soft brush. Rinse thoroughly and dry with a lint-free cloth. Avoid ultrasonic cleaners and steam cleaners, as these can damage the stone or loosen the setting.
• Storage: Store aquamarine jewelry separately from other pieces to avoid scratches. Keep it in a soft pouch or a lined jewelry box.
• Protection: While durable, avoid exposing aquamarine to harsh chemicals, extreme temperatures, and prolonged sunlight, which can potentially fade its color over time. Remove jewelry before engaging in strenuous activities, swimming, or applying lotions and perfumes.

Pros and Cons

Pros:

• Beautiful Color: Its appealing blue and blue-green shades are highly desirable.
• Durability: With a Mohs hardness of 7.5-8, it is suitable for everyday wear.
• Affordability: Generally more accessible in price compared to other blue gemstones like sapphires.
• Variety: Available in a wide range of sizes, shapes, and color intensities.

Cons:

• Color Fading Potential: Prolonged exposure to intense heat or light can potentially cause the color to fade over time.
• Inclusions: While often eye-clean, some specimens may have inclusions that affect clarity and value.
• Treatment Commonality: Many stones are heat-treated to enhance color, which can affect value for purists.

Famous Examples

Several notable aquamarine gemstones have captured attention:

• The 'Dom Pedro' Aquamarine: The largest cut aquamarine in the world, weighing over 10,000 carats. It was discovered in Brazil and is on display at the Smithsonian National Museum of Natural History in Washington D.C.
• Various Royal Jewels: Aquamarine has been a favorite of royalty, and many tiaras, necklaces, and brooches featuring large aquamarines are part of royal collections, particularly in the UK.

Common Misconceptions

• All Blue Beryls are Aquamarine: While aquamarine is a blue beryl, not all blue beryls are automatically aquamarine. The specific trace elements and iron content define the gemstone.
• Color is Solely Natural: Many aquamarines on the market have been heat-treated to enhance their color. While this is an accepted practice, it is important to be aware of it.
• Aquamarine is Extremely Rare: While exceptional, large, deep blue specimens are rare, aquamarine is relatively abundant compared to some other gemstones, making it more accessible.

Related Terms

• Beryl
• Emerald
• Morganite
• Heliodor
• Gemstone
• Faceted
• Lapidary
• Mohs Scale
• Inclusions
• Color Saturation

FAQs

What is the most valuable color of aquamarine?

The most valuable color is typically a deep, rich, pure blue or a vibrant blue-green. The intensity and saturation of the color are key factors, with stones that have a strong, uniform hue being the most prized.

Is aquamarine a good gemstone for engagement rings?

Yes, aquamarine can be a good choice for engagement rings due to its beautiful color and sufficient hardness (7.5-8 on the Mohs scale). However, given its hardness relative to diamonds or sapphires, it may require more care to prevent chipping or scratching, especially in more delicate settings. A protective setting like a bezel is recommended for everyday wear.

Are aquamarines treated?

Yes, many aquamarines are heat-treated to enhance their color saturation and improve their appearance. This is a common and accepted practice in the gem trade. Untreated stones with exceptional color are rarer and generally command higher prices.

How can I tell if aquamarine is real?

Real aquamarine is a natural gemstone with specific physical properties. While professional gemological testing is the most accurate method, some indicators include its hardness (it can scratch glass but should not be easily scratched by a steel knife), its typical eye-clean clarity, and its characteristic cool temperature when held. Its specific refractive index and specific gravity are also distinguishing features that a trained gemologist can measure.

Is aquamarine more expensive than sapphire?

Generally, high-quality aquamarine is less expensive than high-quality sapphire. Sapphires, especially those with a vibrant blue color, are rarer and hold a higher value per carat in the market compared to most aquamarines. However, exceptional aquamarine specimens can sometimes rival the price of lower-grade sapphires.