Abu Yahya Zakariya' ibn Muhammad al-Qazwini (1203-1283) was a Persian physician, astronomer, and geographer from the Persian town of Qazvin. He served as legal expert and judge (qadi) in several localities in Persia and at Baghdad. He travelled around in Mesopotamia and Syria, and finally entered the circle patronized by the governor of Baghdad, ˉAta-Malik Juwayni (d. 1283 CE). Al-Qazwini's most famous work was an Arabic cosmography entitled 'Aja'ib al-makhluqat wa-ghara'ib al-mawjudat, or 'Marvels of Creatures and Strange Things in Existence'. This treatise, frequently illustrated, was immensely popular and is preserved today in many copies. It was translated into Persian and Turkish. Frankincense, also called olibanum (Arabic: lubb?n), is an aromatic resin obtained from trees of the genus Boswellia, particularly Boswellia sacra. It is used in incense and perfumes. There are four main species of Boswellia which produce true frankincense and each type of resin is available in various grades. The grades depend on the time of harvesting, and the resin is hand-sorted for quality.