Blue emeralds are one of the rarest and most valuable gemstones in the world. Unlike traditional emeralds which are green, blue emeralds get their distinct color from trace amounts of iron and chromium in the crystal structure. Only a very small number of emerald mines produce stones with the right chemical composition to create the coveted blue color.
What makes blue emeralds rare?
Emeralds get their green color from trace amounts of chromium and vanadium. The presence of iron in the crystal structure modifies the color and causes a blue hue. But the iron must be present in just the right concentrations – too much iron turns the stone gray or black.
Blue emeralds occur in very specific geological conditions. The levels of chromium, vanadium, and iron must be precisely balanced to produce blue coloring. This unusual combination of trace elements is extremely rare, found in less than 1% of all emerald mining locations.
Colombia is the world’s primary source for fine emeralds, but only three mines – Coscuez, Chivor, and Muzo – have produced blue emeralds. These mines contain trace amounts of iron from surrounding rock that influences the emerald formation. Outside of Colombia, blue emeralds have occasionally been found in Brazil, Zambia, and Egypt but only in very limited quantities.
The rarity of natural blue emeralds has led to innovations in emerald treatments. Some gem dealers use irradiation or heating techniques to alter the color of green emeralds into blue. Most blue emeralds on the market today have been treated to enhance their color. Untreated natural blue emeralds are exceptionally rare.
Natural blue emerald prices
Due to their extreme rarity, natural blue emeralds demand very high prices, even rivaling famous red rubies and blue sapphires. The table below shows some record sales prices for exceptional natural blue emeralds at auction:
| Carat Weight | Price | Sale Date |
|---|---|---|
| 10.11 carats | $17.2 million | 2021 |
| 4.6 carats | $4.3 million | 2020 |
| 6.72 carats | $7.9 million | 2019 |
As you can see, large blue emeralds over 5 carats routinely fetch over $1 million per carat. A 10 carat blue emerald sold in 2021 set a new auction record at over $1.7 million per carat. By comparison, even high quality green emeralds sell for around $10,000-$30,000 per carat depending on clarity and hue.
The enormous price difference arises from the extreme difficulty in finding natural blue emeralds in larger sizes. A 5 carat blue emerald is considered a trophy stone and 10 carats or more is world class rarity.
Evaluating blue emerald quality
Gemologists evaluate blue emeralds using the same 4Cs grading scale as green emeralds:
– Color – The hue should be an intense blue with no gray or green secondary tones. Faint blue is less desirable.
– Clarity – Blue emeralds are commonly included, but the stones should be eye clean with no visible imperfections to the naked eye. Few blue emeralds achieve flawless clarity.
– Cut – Cut quality is extremely important to allow light refraction to maximize blue color. Emerald cuts and octagons are ideal for blue emeralds.
– Carat – Due to extreme rarity, large blue emeralds over 5 carats are most coveted. Prices scale exponentially with carat size above 5 carats.
It takes an expert gemologist to distinguish untreated natural blue emeralds from treated stones. Genuine stones have subtle natural inclusions that are different from treated emeralds. Using a jeweler’s loupe, inclusions in an untreated blue emerald will have feather-like cavities or three phase inclusions.
Blue emerald jewelry
Jewelry designers favor large blue emerald centerpieces in striking creations. Blue emeralds make exceptionally rare engagement rings and are popular in cocktail rings or necklace pendants.
The bold blue color pairs beautifully with colorless diamonds or pink sapphires for contrast. White gold or platinum settings enhance the blue hue. Because of the enormous value, blue emerald jewelry requires special insurance appraisals beyond standard policies.
Investment potential
Natural blue emeralds are one of the most expensive gemstones in the world, even exceeding the cost of similar sized blue sapphires. Their incredible rarity and record-setting auction prices make them a top-tier colored gemstone investment.
As mining deposits continue to be exhausted, blue emeralds will likely become even more scarce in the future. Demand from jewelry connoisseurs and gem investors is rapidly growing, especially in Asia. This rising demand could send prices higher in coming decades.
While lower quality treated blue emeralds are affordable to more collectors, investment-grade natural stones remain safely in the realm of ultra-high net worth buyers. The potential for high returns comes with the tremendous risks of investing in any rare collectible. Proper appraisals are essential for maintaining insurance coverage.
Conclusion
Blue emeralds occupy a sparkling tier atop the gemstone pyramid due to their unparalleled rarity. The unusual geology required to produce blue color restricts mining to just a handful of locations worldwide. Prices reach into the millions for large natural stones over 5 carats. While treated blue emeralds are more affordable, natural stones remains pinnacles of rarity and beauty. For gemstone investors and jewelry connoisseurs, blue emeralds are the apex of preciousness.
