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"
Hooker Emerald Brooch Emerald at the centre of the brooch. Ten pairs of baguette-cut diamonds project between the spokes from behind the emerald towards the platinum band. The Hooker Emerald itself weighs . It measures to a side and is remarkably free of inclusions for its size. The gem's cut gives the appearance of a series of concentric squares within the gemstone (known as a beveled square emerald cut.) In total, the brooch contains approximately of diamonds. The Hooker Emerald was extracted from an unidentified mine in Colombia in the 16th or 17th century. The rough emerald was sent to Europe by Spanish