. 
Dwarves' Earth Treasures Museum: How to ID Agate Roughs
  YellowSkin (orBlackskin?) Agates
.

-Typical colors: Black, gray and colorless
-Typical sizes: Any sizes? Has only one.
-Typical shapes: Pitted dome shape, strongly water-worn.
-Most distinguishing characteristic: Water-worn domed nodules with some yellowing (weathering), chromatographic black and gray colors (similar to Moss Agate from Montana).
-Special Notes: