About Us The QMJ Group Ltd is a privately owned publishing and exhibition business that serves the quarrying, recycling and natural stone industries. QMJ's activities include: 2 MagazinesQuarry Management and Natural Stone Specialist 2 Reference BooksDirectory of Quarries & Quarry Equipment and Natural Stone Directory 2 ExhibitionsHillhead Quarry Exhibition and The Natural Stone Show 1 OnlineAgg-Net - The Aggregates & Recycling Information Network