Definition of "topaz"

Although there are dozens of different types of gems, among the best known and most important are diamond, ruby and sapphire, emerald and other gem forms of the mineral beryl, chrysoberyl, tanzanite, tsavorite, topaz and jade.

2012 March, Lee A. Groat, “Gemstones”, in American Scientist‎, volume 100, number 2, archived from the original on 14 June 2012, page 128

Elgin. Topaz a Saltier and Chief Ruby, on a Canton Pearl a Lyon Rampant Saphyr, which last is their paternal Coat; and the Field Topaz, and Saltier, and Chief Ruby, was the Arms of King Robert the Bruce, they altering the Field from Pearl (as he bore it) to Topaz. / Eglington. Quarterly, 1st and 4th, Saphyr three Flower-de-Lis's Topaz, for Montgomery; 2d and 3d, Ruby three Anulets Topaz, ston'd Saphyr, for the Title of Eglington; [...]

1720, Francis Nichols, Rudiments of Honour, page 296

The Field is Ruby, on a Bend Topaz, three Martlets Diamond. [...] 4. Pearl, on a Bend Diamond, nine Annulets conjoined in three Links Topaz.

1726, John Guillim, The Banner Display'd; Or, an Abridgment of Guillim, page 504

(1) Pearl, a Cross, Ruby, with the Effigies of our Saviour thereon, Topaz, born in Memory of one of the Family's fighting against the Turks. (2) Topaz, a Chief Indented, Saphire. (3) Ruby, three covered Cups, Topaz [...]

1754, John Lodge, The Peerage of Ireland; Or, a Genealogical History of the ..., page 71