The unusual strip-shape diamond crystals were successfully synthesized in the system of Fe-based powder alloy and graphite under pressures of 5.6-5.8 GPa and temperatures of 1600-1650 K in a cubic anvil high pressure high temperature (HPHT) apparatus (SPD-6 x 1200). The synthetic diamond crystals have a strip-shape with light green color. The lengths of the crystals are 0.6-0.8 mm with length to diameter ratios around 2.0-2.5. SEM photographs reveal that the crystals have two main kinds of shapes: one elongated along the (1 0 0) and the other along the (1 1 1) directions. The FTIR spectra of the diamond synthesized indicate that its nitrogen concentration is higher than the normal diamond crystal. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.