Topaz with Limonite Inclusions--"A Member of the 100 Carats Club"

topaz rutilated actually limonite limonated limonite-stained tubes crystallize ribbon-like misnomer greater near-colorless faceted mineral inclusions rutile quartz inclusions--"a staining quite true color used clarity so-called difference better-known carats known similar titanium high member club fact different exceptionally refractive combination displays degree 157.91 measuring persists burma summer 1987 gemological institute america published article journal discussed fills hollow form produce effects dioxide index iron oxide minerals basis natural earth clearly derived difficulty gaining large impressive oval-cut 37.90 needle-like higher goethite yellow-brown pigment public example approximately 29.40 diamond lepidocrocite typically ochre surmise acceptance current weighing 18.20mm