Characteristics of silica in mountain area tapa and sorrounding areas of Tulang Bawang Regency Lampung Province - Rahmadi, Rahmadi; Utama, Hari Wiki; Deliana, Anggi (Faculty of Engineering, Universitas Lampung Jl. Soemantri Brojonegoro No.1 Bandar Lampung, Indonesia 35141, 2025)