This Cluster is dark brown and when light is put on back side the middle is see through. It is 6.5 " length, 2.5 "width and 4.0 " height. What is it and its heavy, no scale so cant weigh.
What about hardness? Try scratching it with several different things; penny, safety pin, pocket knife, ect. this will give an idea of it's Mohs hardness. Also are the crystals hexagonal in shape? A picture from directly above would help.