Based on the word "topaz", the extra "z" makes this flexible domain stand out from the crowd.
Topazz has only six letters and just two syllables. Two-syllable names are extremely rare and extremely sought after. Successful brands using two syllable names include Honda, Walgreens and Dropbox.
Topazz.com is a .com domain. Dot com domains are the most valuable 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.
This domain was first registered in January 2002. Older domains have an advantage when ranking in search engines.