Here is a stunning slab of Psilomelane Marcasite Plume Agate, which is a form of agate and metal! This creates metallic plumes within the agate, for some very awesome highly attractive pattern! This material does have some soft spots, and may need treated to cab!
Measurements (inches - longest - approx): 3.6 x 2.6 x .23
The last photo has been taken dry so that you may see any defects. The other photos have been taken wet to simulate a polish.