Basalt filled with peridotite nodules from the earth's mantle Much peridot that is recovered and faceted by rockhounds and lapidaries, is recovered from the erosion of olivine basalts. Some of these basalts are rich in olivine particularly where basalts have preserved many peridotite nodules such as lherzolite and dunite from the earth's upper mantle. It is interpreted that the basalt is actually a melted by-product of the peridotite. As the magma was created at depth, the peridotite slowly…
