Earth terma (Tib. sa ter; Wyl. sa gter) — a category of terma which employs physical objects.
Dilgo Khyentse Rinpoche writes:
Padmasambhava hid earth treasures in mountains, rocks, lakes, and so on. He then entrusted various protectors, gods, nagas, local deities, and so forth, to guard these treasures until, according to his predictions, the time came to deliver them to the tertön. When the right time comes, the tertön can extract these treasures from their place of concealment.
Examples of earth termas are:
the Tukdrup Barché Kunsel revealed by Chokgyur Lingpa from Danyi Khala Rongo (which Jamyang Khyentse Wangpo also revealed as a gong ter)
the Kagyé Rigdzin Yongdü revealed by Ngari Panchen Pema Wangyal
the Yang Nying Pudri revealed by Tertön Sogyal