The vast expanse of the Islamic world enabled the Muslims to develop natural history based not only on the Mediterranean world, as was the case of the Greek natural historians, but also on most of the Eurasian and even African land masses. Knowledge of minerals, plants and animals was assembled from areas as far away as the Malay world and synthesized for the first time by Ibn Sina in his Kitab al-Shifa' (The Book of Healing). Such major natural historians as al-Mas'udi intertwined natural and human history. Al-Biruni likewise in his study of India turned to the natural history and even geology of the region, describing correctly the sedimentary nature of the Ganges basin. He also wrote the most outstanding Muslim work on mineralogy.