. 
Dwarves' Earth Treasures Museum: How to ID Agate Roughs
  Aperajos Agates

 

Typical colors: Pink, red, orange yellow, and colorless.
Typical sizes: Small, haven't seen any over 7 centimeters long.
Typical shape: Narrow nodules, kind of like teardrops.
Most distingishing characteristic: Thin colorful bands between wider colorless bands in very narrow nodules.