Beryl phase along fractures or within near-surface miarolitic cavities of the rhyolite. Associated minerals include bixbyite, quartz, orthoclase, topaz, spessartine, pseudobrookite and hematite. Beryl Beryl ( ) is a mineral composed of beryllium aluminium cyclosilicate with the chemical formula BeAlSiO. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, red (the rarest), and white. Beryl is also an ore source of beryllium. The name "beryl"
Trapiche emerald Trapiche emerald Trapiche emerald is a rare variety of the gemstone emerald, characterized by a six-pointed radial pattern of ray-like spokes of dark impurities. It is one of several types of trapiche or trapiche-like minerals, which also include trapiche ruby, sapphire, garnet, chiastolite and tourmaline. The name comes from the Spanish term "trapiche", a sugar mill, because of the resemblance of the pattern to the spokes of a grinding wheel. Trapiche emeralds were first described by Émile Bertrand in 1879. They are generally only (and rarely) found in the western part of the Eastern Cordillera basin, in the Muzo, Coscuez