Kingman has a long history that is told in Turquoise in America Parts 1-3. The dark web, first called cob web, is very rare as natural and is often surface treated to darken the matrix.
 
This cab weighs 52.1 carat and measures 3.75cm X 2cm X 8mm. It is priced at $90 a carat or $4689. It is not treated and is backed. I have assigned a TG of 91 or GG. I purchased the rough from Greg Schaaf who purchased it from Marty Colbaugh and I cut the cab. White spot is camera flash.