With its incomparable lush green hue, emerald is one of the most sought-after and valuable gemstones of the world. However, few have seen or even heard of a much less common variety called Trapiche Emerald.
Trapiche emerald is a very rare natural occurring phenomenon. Unlike asterism in rubies and sapphires, the ‘star’ pattern in Trapiche emeralds are caused by the simultaneous hexagonal growth of albite along with the emerald crystal.
Excerpted from Bonham’s (17 May 2011 13:00 EDT New York Natural History – Minerals):
Trapiche emeralds are in a class by themselves and are perhaps the rarest and most memorable of “pattern” gems—certainly the most unusual amongst the big three of emerald, ruby, and sapphire. Trapiche is the Spanish word for a spoked wheel used to grind sugar cane, which bears a striking resemblance to the pattern in these emeralds. Normally they are cut en cabochon to display the beautiful spoke-like star.
Their known locality is the famed Muzo Mine District. Their six spoke-like albite “rays” emanate from a hexagonal center with the areas in between filled with lively green emerald. These rays, which appear like asterism, are not caused by light reflections from tiny parallel inclusions (as are stars), but from white albite feldspar impurities that happen to form in the same pattern.
The earliest reference of trapiche emerald was in an 1879 French mineralogical bulletin. Since then, it has been rarely commented upon. Gemological examination shows that the trapiche is a single crystal and not a twinned specimen as was originally thought. Trapiche emeralds are valued based on a number of factors; saturation and even color, clarity, size and the most important being the definition, completeness, and centering of the “rays.”
The finest quality Trapiche emeralds are usually cut into round or oval cabochons to best show off their patterns. However, in recent years, slices and more ‘rough’ looking cuts have come onto the market.
- EMERALD GREEN – > Pantone Color of 2013 (siamgempalace.wordpress.com)