The Grain De-Stoner is designed for effective removal of stones and iron, dirt, glass and other heavy materials from crops, i.e. sunflower seeds, kernels, water melon seeds, wheat and rice, etc. The materials passes on an inclined oscillating fish-skin like screen. Materials and high density waste are separated using upward current air passed with the help of a blower. The heavy materials (stones) fall through the air stream and are discharged from stone outlet. Grains sus pended then sink down to grains outlet. Air volume and angle can be adjusted to meet an optimal degree of separation according to different materials. In addition, the excellent removal of high-density impurities like stones protects the downstream processing equipment and thus perceptibly reduces its wear and tear.