Aquamarine is a light blue-green variety of the mineral beryl. The name aquamarine comes from the Latin for seawater, and reflects the lovely blue-green color that is most commonly associated with this gemstone. However, some aquamarines can display greenish hues as well. Here’s a closer look at the range of colors found in aquamarine.
The Cause of Color in Aquamarine
Like other varieties of beryl, including emerald and morganite, aquamarine gets its color from trace amounts of minerals present in the crystal structure. The main mineral impurity responsible for aquamarine’s color is iron. Iron can occur in two different oxidation states in beryl: Fe2+ (ferrous iron) and Fe3+ (ferric iron).
The Fe2+ state produces a bluer color in aquamarine, while Fe3+ lends a more yellowish-green tint. Most aquamarines strike a balance between these two iron states, resulting in the pale blue-green hue that is typical of this gem. However, subtle variations in the iron content and oxidation states can create aquamarines with greener or bluer shades.
The Greenish Hues of Aquamarine
While light blue is the most prized color for aquamarine gems, some stones can display distinct greenish overtones. These greenish aquamarines occur when the gem contains a higher concentration of Fe3+ relative to Fe2+. The greater presence of ferric iron shifts the balance towards green in the color mix.
Additionally, heat treatment can enhance the green tints in an aquamarine. Heating is commonly used to improve the clarity of aquamarine by removing or reducing mineral inclusions. As an added effect, heating tends to promote the ferric state of iron, increasing the yellow-green hues. Darker green aquamarines may obtain their color from heat treatment combined with a high ferric iron content.
| Aquamarine Color | Cause |
|---|---|
| Light blue | Higher Fe2+ (ferrous iron) |
| Blue-green | Mix of Fe2+ and Fe3+ (ferric iron) |
| Greenish blue | Higher Fe3+ |
| Dark green | Very high Fe3+, potentially with heat treatment |
This table summarizes how the iron content and oxidation states influence aquamarine’s range of blue-green hues.
Evaluating Greenish Aquamarines
In the gem trade, pure green aquamarines are less valued than blue stones. The most prized aquamarines display a vivid, slightly greenish blue – think the colors of the ocean or a tropical lagoon. These lively blue-green tones command higher prices.
Aquamarines with distinct yellow-green secondary hues are considered less desirable. Whileheat treatment can enhance aquamarine’s clarity, excessive heating produces an undesirable greenish cast. Most collectors prefer the soft blue-green tones created by a balance of ferrous and ferric iron.
However, greenish aquamarines can still make beautiful, lower-cost gems. Stones with medium tones and moderate saturation can appeal to buyers who enjoy unique colors. Lightly included aquamarines with distinct green secondary hues are suitable for jewelry use and can make one-of-a-kind pieces.
Famous Greenish Aquamarines
While rare, some famous aquamarines display a perceptible green tint. Here are a few noteworthy examples:
- The Dom Pedro aquamarine – This large, oblong cabochon weighs over 1,000 carats. It was crafted in the 18th century for a Portuguese king and has a rich blue-green color.
- The Maraquita aquamarine – Mined in Brazil in 1910, this 898-carat emerald cut displays distinct greenish hues. It is part of the Smithsonian Institution’s gem collection.
- The Rockefeller aquamarine – At 100.32 carats, this rectangular step cut has seafoam green tones. It sold at auction in 2021 for over $5 million.
These famous aquamarines demonstrate that greenish blue stones can still possess exceptional beauty, quality, and value in rare cases.
Identifying Greenish Aquamarine
Distinguishing aquamarine from similar greenish gems takes an expert eye. Here are some tips for identifying aquamarine:
- Color – Look for medium-light tones ranging from greenish blue to blue-green. Avoid dark or pure green stones.
- Clarity – Aquamarine typically forms with minor flaws. Few are eye-clean.
- Hardness – With a Mohs hardness of 7.5 to 8, aquamarine is suitable for most jewelry.
- Crystal shape – Six-sided prism terminations are typical.
- Specific gravity – Around 2.68 to 2.74 for aquamarine.
- Refractive index – 1.567 to 1.590.
- Pleochroism – May display bluish and yellowish-green pleochroic colors.
Advanced testing can verify aquamarine’s chemical composition of beryllium aluminum cyclosilicate. The presence of iron can also be confirmed.
Differentiating from Similar Gemstones
Aquamarines with greenish hues can resemble several other gems. Here’s how to tell them apart:
| Gemstone | Distinguishing Features |
|---|---|
| Emerald | Much darker green color; highly included |
| Green tourmaline | Higher clarity; stronger pleochroism |
| Green beryl | Pure green without blue tones |
| Green apatite | More yellowish green; lower hardness |
| Peridot | Higher clarity; deeper olive green |
| Green garnet | Greater saturation; higher refractive index |
Careful observation of color, inclusions, hardness, cut, and other gemological features can identify greenish aquamarine.
Enhancing Greenish Aquamarines
Most aquamarines undergo some treatment to improve their appearance. Here are some common enhancement techniques:
- Heat treatment – Heating can minimize inclusions and intensify greenish hues. Temperatures may reach 450-700°C.
- Irradiation – Exposing aquamarine to radiation can induce desirable bluish tones. Gamma rays and electron beams are often used.
- Coatings – Thin chemical or lacquer coatings can mask flaws and improve color consistency in aquamarine.
- Dyeing – Greenish aquamarine is rarely dyed, but blue dyes may be applied to enhance color.
- Fracture filling – Oil, resins, and polymers can dramatically improve the clarity of included stones.
Reputable sellers will disclose any treatments. Look for irradiation and heat treatment in greenish aquamarines.
Aquamarine Origins and Sources
Aquamarine forms in granitic pegmatites across the globe. Top sources for greenish aquamarines include:
- Brazil – Minas Gerais deposits produce large, high-quality greenish blue aquamarines.
- Pakistan – The mountains of Gilgit yield abundant aquamarine rough with green hues.
- Mozambique – Marropino mines complex hosts gem-rich pegmatites with greenish aquamarine crystals.
- Madagascar – Smaller greenish aquamarine specimens originate from Mananjary and Ifanadiana regions.
- Russia – The Ural Mountains yield lightly greenish aquamarine gems.
- United States – Colorado, North Carolina, and California produce some collector-grade greenish crystals.
Brazil remains the world’s primary source, exporting over 80% of all natural aquamarine crystals on the market.
Buying Greenish Aquamarine
Here are some tips for buying greenish aquamarine:
- Inspect color carefully. Subtle green undertones can affect value.
- Review clarity – look for eye visible inclusions under magnification.
- Verify any treatments – irradiation and heating are likely.
- Examine cut quality – step cuts show color best.
- Request lab certification from reputable gem labs.
- Compare prices across multiple sellers.
- Consider buyer protection with certified gemologists and return policies.
- Review any special care instructions.
Taking time to properly evaluate and source aquamarines can help buyers get optimal value.
Caring for Greenish Aquamarine
While fairly durable, aquamarine requires some basic care. Here are some tips:
- Store aquamarine separately to prevent scratches.
- Clean with warm water, mild soap, and a soft brush.
- Avoid harsh chemicals, heat, and ultrasonic or steam cleaning.
- Protect aquamarine from sharp blows that can cause fractures.
- Remove aquamarine jewelry before physical activities.
- Have stones checked by a jeweler after any repairs or sizing changes to settings.
With proper care, greenish aquamarine will remain beautiful for many years.
Using Greenish Aquamarine in Jewelry
Thanks to its beauty and durability, aquamarine shines in many jewelry designs. Here are some tips for using greenish aquamarine:
- Flatter the color with white metals like platinum or white gold.
- Step cuts like emerald cuts and baguettes best display greenish hues.
- Surround with white diamonds or clear stones for complementary contrast.
- Incorporate aquamarine into nature-inspired settings with leaves, vines, waves, etc.
- Feature aquamarine as a center stone or accent stones in rings, pendants, and earrings.
- Use lighter greenish aquamarines in everyday wear rings and bracelets.
- Reserve pure green aquamarines for occasional wear pieces.
With its refreshing color, aquamarine suits modern, minimalist jewelry styles very well. Its blue-green tones provide a dash of color perfect for everyday wear.
Aquamarine Engagement and Wedding Rings
While not a traditional choice, aquamarine can make a stunning alternative engagement ring. Its durability, availability in large sizes, and gorgeous light color make it well-suited for daily wear.
For those who prefer something beyond a standard white diamond, aquamarine provides a refreshing pop of color. Creative settings can allow it to stand out or complement other gems. Modern brides looking for something unique are drawn to aquamarine.
Aquamarine also works beautifully in non-traditional wedding and anniversary bands, either as a center stone or accent stones alternating with diamonds. The greenish blue tones add personality while still remaining neutral enough for everyday.
Larger greenish aquamarines can make impressive statement pieces. Designers can also incorporate many small stones for a glittering effect. With so many options, aquamarine gives engaged couples creative alternatives to standard diamond rings.
Aquamarine in Men’s Jewelry
Aquamarine’s cool tones and bold sizes make it appealing for men’s jewelry:
- Rings – Large emerald cuts or rectangular steps work well.
- Bracelets – Multiple aquamarines can become bold cuff links.
- Pendants – Greenish aquamarines stand out against dark shirt colors.
- Watches – Aquamarines lend color to sleek watch faces and bands.
Faceted shapes and clean designs complement aquamarine’s crisp color. This gem gives masculine jewelry and watches a subtle yet stylish pop of color.
Conclusion
Aquamarine captivates with its refreshing greenish blue hues, unlike any other gem. While the purest blue examples fetch the highest prices, greenish aquamarines can provide beautiful and affordable alternatives. Their light green-blue tones offer a unique take on this classic gemstone.
With proper care and optimal cuts that highlight its color attributes, greenish aquamarine makes a distinctive addition to any jewelry collection. Both modern and traditional settings benefit from its cool, evocative tones.