This set is carved from rock crystal in Egypt in the 10th century. The set is incomplete as pieces were carved according to the crystal available, but the pieces are 2.5–4.5 cm high, 1.9–3.1 cm long with a width of 1.8–3 cm. Taken from Qantara.
From Egypt it was exported to Spain, where it ended up in the Collegiata de Àger (via Google Translate). The set has three queens, three bishops, two knights, a castle, ten pawns, and a rook in the shape of a molar.
This rook is in the Al Sabah Collection in Kuwait (go to the Jewellery and jewelled objects collection). However, this piece is 4.22cm high & 4.75cm wide and thought to be from Iran in the 9th-10th century.
Pieces Crystal and Osnabruck Set on Carolus Chess.