If it’s made from solid carbon, it could easily weigh in excess of 500kg
1m^3 of carbon weighs ~3500kg, choosing the most appropriate form of carbon for interior decoration.
A 500kg (or, using the preferred measurement, 2,500 000 carats) sofa would cost appx. $12,500,000,000 assuming diamonds of a reasonable quality, and would be extremely uncomfortable, impractical and fragile, despite looking amazing.
If you bought this a few years back, you could have swapped it for Motorola. 
