This is a flint or chert arrowhead that dates to the Neolithic period (approx. 10,000 years ago). It was recovered from the western Saharan Desert in Mauritania. These are remnants from original inhabitants of the area, which was more of a sparse grassland and not the barren desert it is today. These arrowheads typically have a variety of shapes, sizes, and colors, according to the material used and the purpose it was intended for.
Refer to the photo. The black centimeter cube is shown for scale and is not included.. You get the arrowhead shown. It measures approx. 22mm in length x 15mm in width.