Imperial Topaz Crystal Specimens “A Quality” Size #1 This is an “A” quality stone, the clarity on each stone is nice while some dark patches of iron-based natural inclusions are present on few stones. These “A” quality imperial topaz is not as clear under light and have darker orange tones but still shine beautifully under light. Topaz rates an 8 on the hardness scale. It is a hard brilliant stone with a fine colour range. In fact, the colour of topaz is more important than the size in determining its value. This Brazilian imperial topaz can often have a bright yellow to deep golden brown hue. The term “imperial topaz” refers to the reddish-orange colour the deep golden yellow.