Topaz is commonly associated with silicic igneous rocks of the granite and rhyolite type. It typically crystallizes in granitic pegmatites or in vapor cavities in rhyolite lava flows like those at Topaz Mountain in western Utah. It may be found with fluorite and cassiterite. It can be found in the Ural and Ilmen mountains, Afghanistan, Czech Republic, Germany, Norway, Pakistan, Italy, Sweden, Japan, Brazil, Mexico, and the United States.
Topaz crystals from Brazilian pegmatites are up to 80 cm x 60 cm x 60 cm in size. The biggest topaz crystal ever found, named “El Dorado”, was found in Brazil in 1984. It weighs 6.2 kg and belongs to the British Royal Collection. The famous Braganza diamond is in most likelihood a Topaz. The Topaz of Aurungzebe, observed by Jean Baptiste Tavernier measured 157.75 carats.