This bathtub is made of Natural Black Basalt Stone
An organically shaped, hand cut stone bathtub, hot tub or soaking tub made from a single river boulder. Look at the pictures of this beautiful work of art and check out the interior and exterior textures and colors. Incredible!This bathtub is heavy, so you'll need to plan ahead and ensure your floor can handle the weight. The stone (basalt) is very hard and easy to maintain. Simply clean the bathtub bowl and top edges with a normal, non abrasive bathroom cleaner.Standard 2" drain size.
HZX STONE also supply basalt stone sink, basalt tile, basalt cobble stone, basalt flagstone and so on, welcome for any inquiry if need.
https://www.hzxstone.com/stone-sink/natural-black-basalt-bathtub.html