I have a stock of polished colored Onyx (picture attached).

12"x 12"x 1.5 cm in USA. 5000 sq ft. @ FOB $12.60 
(polished onyx pasted on other marbles with color in between.)

I would sell the whole lot at $11.50 /sq.ft. Red, Pink, Blue and Purplish.
Approx 1250 sq.ft each color total 5000 sq.ft.