Phytoliths are formed from minerals in ground water that can be deposited in, and between, the cells of the plant as opaline silica (glass). The quantity and quality of the phytoliths formed in any plant will depend on many environmental factors and also the species of plant. Therefore, when the plant degrades, the phytoliths remain as microscopic glass skeletons of the plant cells allowing the phytolith analyst to determine the types of plants present in the deposit. This can give the archaeologists clues to the nature of climate, economy, crop processing and even furnishings like rush mats or baskets.