A Koran found in China is thought to be the smallest in the world.It is 1.9 centimetres long, 1.3 centimetres wide and 0.6 centimetres thick.The Guinness Book of Records currently lists a Koran owned by an Indian couple as the smallest. It measures 2 centimetres by 1.5 centimetres by 1 centimetre.

The contender to the title is kept in an iron box at Ningxia Museum in China's north western Ningxia Hui Autonomous Region.
It weighs 1.1g and is covered with mauve kraft paper with ethnic designs, the Egyptian national emblem and Arabic text. The text reads: "This is a worshipful Alcoran, only people with clean mind and body can carry it, Islamic Calendar 1312." (1892 A.D.)
source: http://www.ananova.com/news/story/sm_590062.html