Study on light and heavy minerals in red soils developed from basalt, and in red soils and mountain yellow soils developed from granite showed that (1) the contents of heavy minerals in red soils, derived from basalt were much higher than that in other red soils, especially Xuwen laterite in which the contents of heavy minerals were about 90% in 10-50 μ frac lion, 35-65% in 50-100 μ fraction, and 6-33% in 100-250 μ fraction, as compared to less 6% in most of soils such as red soil derived from granite. In fact, many heavy mineral grains in red soils derived from basalt consisted of quartz coated or cemented with ferric oxide which could not be removed by boiling 10% HCl. As is known to all, the specific gravity of quartz is 2.65, while that of quartz grains enveloped or cemented by ferric oxide raised to over 2.9, thus the quartz became "heavy mineral", and resulted in the increase of heavy mineral content in this soil.