Nero Mist granite countertop
I sealed some nearly black granite over 20 years ago and it never needed resealing. The first time food oil touched it , it made a mark in the granite. So I went to the dealer and he sold me a 500 ml bottle of a clear oil-like liquid. It worked great; it needed less than one ounce/sq.yd. ... Found it in my garage- PSI, premium silicon impregnator ( Lithofin brand), made in Germany.