Rare Trapiche Emerald Crystal
Coscuez, La Peña Blancas
Muzo Mining District, Columbia
Trapiche emeralds are in a class by themselves and are perhaps the rarest and most memorable of "pattern" gemscertainly 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 present specimen is rare for its size, the saturation of its vivid green color, the completeness of the crystal and its well-formed spoke pattern.
Weighs approximately 51.6 carats (10.3g); Measures 1 x 1 x ½ in