GO 340 Gemstones & Gemology
ES 567 Gemstones of the World
Dr. Susan Ward Aber, Geologist & Gemologist
Emporia State University
Emporia, Kansas USA

academic.emporia.edu/abersusa/go340/topaz.htm

Natural Topaz Crystals, Minas Gerais,
Brazil, weight 69.5 kg (153 lb),
50.4 kg (111 lb).
Smithsonian National Museum
of Natural History.
Photos by S.W. Aber, 2009.

Topaz

Topaz is a nesosilicate, Al2[(F,OH)2/SiO4], and 8 on the hardness scale. It is in the orthorhombic crystal system, which is reflected in the commonly found prismatic crystal form with orthorhombic pyramid terminations. It has perfect basal cleavage, as well as a conchoidal and uneven fracture. Topaz is transparent and translucent, with a vitreous luster, and high specific gravity, 3.49-3.57. It is doubly refractive, 1.609-1.643, with a strong to definite pleochroism (with the exception of blue topaz, which as weak to none), and weak fluorescence. When topaz is gently heated or rubbed, it becomes electrically charged. Topaz occurs in cavities within granite or rhyolite igneous rock, pegmatite dikes, high temperature quartz veins, and/or alluvial deposits ( The Mineralogy Database). Inclusions are tear-shaped cavities. Read about mining from, Topaz Visiting the Mine, http://www.secretsofthegemtrade.com/articles_11.htm, an excerpt from R. Wise, Secrets of the Gem Trade.

Oh so interesting You Tube... The Topaz Adventure: Rick Mining Topaz in Utah! See Rick Seng
camping, hiking, and extracting a large gem topaz crystal in ryolite...

If the embedded video does not play, visit http://www.youtube.com/watch?v=dxL0bmVfv5c&feature=player_embedded

According to Schumann (2011) and gemlore, topaz has healing properties and are purported to cure varicose veins (p. 290)! In times past, all yellow, golden brown, and sometimes green gems were called topaz. Topaz may be colorless, yellow, red-brown, light blue, pink-red, red, violet, and light green. The most common color is yellow with a reddish tint, while the most valuable color is pink to reddish-orange. This pink to reddish-orange is referred to as Imperial topaz. A red-brown topaz is called rootbeer topaz and is more expensive than citrine quartz, but less expensive than morganite beryl (theimage.com). Some yellowish-brown topaz will fade in sunlight and natural blue topaz is fairly rare. For some great images of natural pale blue topaz and more, see John Betts photos at AllMinerals.com, Online Mineral Museum. This is worth the detour!

  • Imperial topaz from Brazil, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=20021
  • Unusual Brazilan Imperial topaz in iron-rich matrix instead of the more common weathered clay matrix, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=38066
  • Rare blue topaz crystal from Zimbabwe, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=16666
  • Pale blue pebble from Nigeria, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=28706
  • Internally flawless, colorless or white topaz from Brazil, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=12925
  • Internally flawless, colorless topaz crystal from Burma, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=21173
  • Pink and orange bi-colored topaz from Brazil, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=24737
  • Rare pink columnar topaz crystal from Brazil, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=30742
  • Deeply colored pink orthorhombic crystal from Pakistan, http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=21615

    Topaz Photo Gallery from The Image:


    Topaz from
    Topaz Mountain, Utah
    from The Image

    Topaz from
    Thomas Mountain, Utah
    taken from The Image

    Rootbeer topaz
    taken from The Image

    Blue topaz
    taken from The Image

    Carved blue topaz
    The Image

    Image from
    Mineral and Gemstone
    Kingdom

    Clear or white topaz with rutile,
    taken from The Image

    Clear or white topaz with rutile,
    taken from The Image

    Close up of rutile
    taken from The Image

    Topaz is the November birthstone and the 4th anniversary gem. For more details, visit Jewelry Central. Topaz is also serves as the gemstone of the state of Texas. The name is believed to be derived from its place of discovery, Topazos (now Zebirget or St. Thomas Island), an island in the Red Sea. The main gem topaz deposits are in Brazil and Russia. Other locations include Mexico and in the U.S., Texas, Colorado, and Utah. Location listings may be viewed at mindat.org.

    Synthetic blue topaz has been on the market since 1976 and some clear to yellowish topaz will turn to various shades of blue with heat or irradiation treatments. Topaz is often imitated by varieties of quartz. Yellow heat treated amethyst and citrine quartz have been known by the trade names such as Gold topaz, Madeira topaz, False topaz, Brazilian topaz, Citrine topaz, whereas brown to black quartz has been called Smoky topaz. Quartz is often substituted for topaz as a birthstone in jewelry, many people would not recognize the natural topaz. The term Imperial topaz and Precious topaz are both referring to topaz, but Oriental topaz is golden sapphire. Other names include silvery topaz (colorless topaz), sherry topaz (orange-brown topaz), London Blue topaz (deep blue, irradiated topaz), Swiss Blue topaz (medium dark blue topaz, heat treated), Brazilian ruby (pink topaz) and Brazilian sapphire (blue topaz). .


    Imperial topaz
    taken from The Image


    The material for this section came primarily from:

    Return to the Syllabus or choose another gemstone below.

    Alexandrite Amber Amethyst Chalcedony Diamond Emerald
    Garnet Jade Malachite Opal Pearl Peridot
    Ruby Sapphire Tanzanite Topaz Tourmaline Turquoise

    This page originates from the Earth Science department for the use and benefit of students enrolled at Emporia State University. For more information contact the course instructor, S. W. Aber, e-mail: esu.abersusie@gmail.com Thanks for visiting! Webpage created: November 5, 2000; last update: November 19, 2012.

    Copyright 1999-2012 Susan Ward Aber. All rights reserved.