Often rivaled but never equaled by citrine, topaz, just like emerald, is a silicate with a high refraction 
index, which makes this stone a much sought-after item. It is hard: only diamond, ruby or sapphire can scratch it. 
From yellow topaz to blue topaz, there is an infinity of colour varieties, some of which are not natural (the pink is obtained by heating). But the most sought-after variety, the imperial topaz from Brazil, has a light honey colour with an almost imperceptible touch of pink. 
Topaz deposits are located in Brazil, Madagascar, Africa, Russia, Sri Lanka, etc.