Black Asbestos Cement Lab Countertop
Example of black asbestos-cement laboratory countertop. Often mistaken as "slate" or granite; this material demonstrates its fibrous nature at a small, localized area of damage shown in the detailed inset image. This fibrous cement material is also sometimes referred to as "Transite" (a former proprietary brand tradename by Johns-Manville).
Also found in several other colors, but black being the most common in many laboratories and workrooms inside schools, colleges, and commercial & governmental testing organizations. Not uncommon to find graffiti carved into the counter surfaces in high school settings or to find localized areas of excessive wear from long-term repetitive contact which can degrade the surface and expose the asbestos fibers.