Lusterware tiles at the Alhambra.

It is forbidden in Islamic culture to make images of sentient beings for this reason the artists of the Islamic world excelled in the use of pattern, written letters, geometric and abstract floral patterns.

This photo is of glazed tiles which are called azulejos in Spanish. Note that the tiles are lustered. Lusterware or Lustreware is a type of pottery or porcelain with a metallic glaze that gives the effect of iridescence. It is produced by metallic oxides in an overglaze finish, which is given a second firing at a lower temperature in a "muffle kiln", or a reduction kiln, excluding oxygen. The discovery of this technique can be traced back to the 7th century A.D. when Islam emerged in the city of Mecca.