Based on the word "topaz", the extra "z" makes this flexible domain stand out from the crowd.
The name "topazz" has only six letters and just two syllables. Two-syllable names are very rare and extremely sought after. Successful brands using two syllable names include Delta, Subway and Disney.
This domain was first registered in January 2002. Older domains have an advantage when ranking in search engines.
Topazz.com is a .com domain. Dot com domains are the most valued top-level-domain in the world, used by famous websites like facebook.com. When you own a .com, it is much easier to rank for your own name in search engines.