This listing is a square cabochon of spiderweb turquoise
The weight of this stone is is 29.5ct. and measures 21mm x 5mm in thickness.
I recently cut this stone and it is some of the hardest turquoise I've worked with. This was cut from a slab that seemed to be enhanced for color on one side. Color is a very dense dark blue with black webbing. I think it's Chinese but not sure. I purchased the slab in 1989 in Tuscon, AZ.