Mastic (Greek: Μαστίχα) is a resin obtained from the mastic tree (Pistacia lentiscus). In pharmacies and nature shops, it is called "Arabic gum" (not to be confused with gum arabic) and "Yemen gum". In Greece, it is known as the "tears of Chios," being traditionally produced on that Greek island, and, like other natural resins, is produced in "tears" or droplets.
Originally a sap, mastic is sun-dried into pieces of brittle, translucent resin. When chewed, the resin softens and becomes a bright white and opaque gum. The flavor is bitter at first, but after some chewing, it releases a refreshing, slightly pine or cedar-like flavor.
The word mastic is derived from the Greek verb, μαστιχειν (mastichein) "to gnash the teeth", which is also the source of the English word masticate. The word mastic is a synonym for gum in many languages. The Arabic word for mastic, al-maṣṭika (Arabic: المصطكى), has also been applied to chewable gum resins from species of frankincense. The same is true of its Aramaic/Hebrew cognate (מצטכי)
Mastic has been harvested for at least 2,500 years since Greek Antiquity. The first mention of actual mastic 'tears' was by Hippocrates. Hippocrates used mastic for the prevention of digestive problems, colds and as a breath freshener. Roman emperors used mastic along with honey, pepper, and egg in the spiced wine conditum paradoxum. Under the Byzantine Empire, the trade of mastic was made the emperor’s monopoly. In the Ottoman Empire, the sultan gathered the finest mastic crop to send it to his harem.
During the Ottoman rule of Chios, mastic was worth its weight in gold. The penalty for stealing mastic was execution by order of the sultan. In the Chios Massacre of 1822, the people of the Mastichochoria region were spared by the sultan to provide mastic to him and his harem. Sakız Adası, the Turkish name for the island of Chios, means "island of gum". The mastic villages are fortress-like, out of sight from the sea, surrounded by high walls and with no doors at street level, meaning that the villages were entered only by ladders) in order to protect the sap from invaders.