Known for its unique natural heritage in Qatar, Bin Ghannam Island – located in the Khor Al Shaqiq Bay – was studied by European and Qatari archaeologists in the second half of the 20th century. Their excavations revealed a pile of approximately 2.9 million crushed shells of the murex (Thais savignyi), a sea snail of the Muricidae family that lives under rocks in the intertidal basin. When crushed, the shell releases the hypo-branchial gland which, when in contact with light, produces a dark red dye, purple. Large ceramic vessels from the 13th and 12th centuries BC used to macerate the crushed molluscs have also been uncovered. A temporary settlement for trade with Bahrain, the island was home to fish and pearl fishermen from the early 2nd millennium BC.