Nero Black Origin: Africa Block sizes: Normal dimensions. Special big blocks possible Colour uniformity: Excellent Availability: Limited Material used for: interior exterior Polishing treatment: Excellent Other surface's treatments: Well. specially the sand blasting General comments: Material quarried not in big quantity. Possible the use for big jobsafter an axact check of quarry's engagements. Special care is requsted to avoid the presence of "cat's footmarks". Examples of tests' results: 1. Compressive strength 2777/3188 Kg/sq.cm. 2. Ditto after gelivity 2696/3071 Kg/sq.cm. 3. Water absorption 0.015% 4. Ultimate tensil strength 274/343 Kg/sq.cm. 5. Impact test-min.fall height 65/75 cm. 6. Coef. thermal expans 5.90 7. Abrasion coefficient 4.58 x 10 (-6) 8. Bulk density 2960 Kg/m3. 9. Elasticity module 1030000 Kg/sq.cm. 10. Knoop microhardness --- 11. Flexural strength --- 12. Porosity ---       Затвори