Nice Spanish sphalerite specimen with great gemmy quality that really allows its intense yellow, orange, and red coloration to be seen with a bit of backlight. The piece itself is an undamaged floater with variable luster and some etching patterns and decent aesthetics, but I think it would probably make for a rather excellent piece of rough since its interior is fairly clean, it is quite large, and there are only some minor internal cracks. Also, it is just the right color intensity for faceting, not dark enough to obscure the internal reflections but just right for the color to open up as saturated oranges and reds once cut into brilliants.