Properties and nature / Characteristics and essence

(1) The crystal form of topaz is a right-angled parallelogram and rectangular prism. (2) Its hardness ranges from 8 to 9. Therefore, it can cut quartz/crystal and is cut by diamond and sapphire. (3) Its luster is vitreous (glassy). (4) Its color includes yellow, white, orange-cinnamon, bluish, pink, onion-skin, yellowish-white, greenish-white, mountain green, sky blue, crimson, flesh red, etc. Yellow topaz is extremely fine and attractive. The deeper this color is, the higher its value. Regarding the pink shade, these are its designations:

(1) Pink topaz: This is produced from yellow topaz by placing deep yellow topaz into a hookah bowl or a small crucible, covering it with ash or sand, and subsequently applying mild heat, which turns its color from yellow to pink. If the color turns out fine, its value increases. It is also called Brazilian topaz. (2) Red topaz: Topaz of this color is rare/prized. Crimson shades are often seen. (3) Bluish topaz: This is a fine, pleasing color and is not particularly rare. Pale-colored aquamarines are sometimes purchased in its place. (4) White: Also called Minas Novas. It is set into armlets, necklaces, and other ornaments. (5) Specific gravity: 3.2. (6) Transparent and lustrous. (7) Reflective power / Refractive index. (8) Electricity is generated through friction and heat. The electric property of Brazilian topaz was first discovered in 1760 by a person named Canton. Abbé Haüy observed this same property in Siberian topaz, noting that this electrical charge can persist in topaz for 20 to 24 hours. Sir David Brewster observed a strange phenomenon while cutting a topaz that had several cavities containing an extremely expansive liquid substance. His purpose was to make an incision on a cavity, open it, and examine its liquid matter. Upon opening the cavity, two rapidly expanding fluids began flowing over the polished facet, gradually expanding and contracting. Sometimes they would contract into a droplet, and at other times expand and widen. This movement continued until they vaporized completely. There is no doubt that this movement was due to the electrical charge generated by the cutting. (9) Its composition consists of 58.38 parts alumina, 34.01 parts silica, and 7.61 parts fluorine. (10) If placed on charcoal and heated using a blowpipe, it does not melt. However, if heated with borax, it turns into a colorless glass-like state. If subjected to intense heat, bubbles appear on it, which immediately burst. Yellow topazes become colorless with heat. Dark yellow ones turn pink or a Hessonite-like red. With cobalt nitrate solution/acid, it turns blue.