Chronos
This image represents Chronos, the personification of time.
After a little research I saw that he is usually portrayed through an old, wise man with a long beard.
The spiral circle of particles represents the time floating (like sand dropping inside an hourglass).
The twelve semicircles represent the hours on a clock, or the Zodiac Wheel (Chronos was depicted in Greco-Roman mosaics as a man turning the Zodiac Wheel), or the month of the year (his name in Modern Greek also means "year").
And yes, I love using black & gold...