I’ve had a sweet chunk o’ granite for about 9 years that I’ve always wanted to turn into a clock.
I had to drill a hole in the bottom to get the control and charging wires out.
Adafruit sells a fun, individually addressable RGB LED ring. The microcontroller is a Flora. Timekeeping is handled by a Chronodot RTC. 
The big cap is there to protect the Neopixels as per Adafruits best practices. I don't think it's really needed in this project since the power source is either LiPo batter or the charger. Better safe than sorry.
There's a 5-way button on the back for future use. 
Power is supplied by a LiPo 
And here is the near finished product. 
Watch it work :)
The code is written to emulate a water clock with an hour tube (left) and a minute tube (right). Each dot on the hour side represents one hour and each dot on the minute side represents 5 minutes. Every minute a "drop" falls down the minute side, and every 5 minutes another dot "fills up". The hours drip and fill once each hour. At the end of the hour the minutes side "drains" out and starts over. The hour side drains at noon and midnight. You can see this in action in the videos below.