EMU
These Emu eggs are fascinating. Not too much smaller than the Ostrich, but a dark avocado color.  The photo looks more black, but that's dark green you're looking at.  Scratch the surface and you get a light green.  Keep scratching and you'll work thru 7 layers of color to a white before you scratch thru.  I understand the aborigines in Australia do it with stone.  Takes a while.  Took me hours to do one and I used a dermal tool.  Bought this here in Colorado.  A gentleman in North Denver, Adams county was raising Emu's.  They are a funny looking bird and the feathers they grow have three spines to them, soft and misty feeling.