Monsoon Season Blue-Green Rock and Boulders Central California quarry producing a wide range of materials from D. G. fines to very large boulders. Materials are shipped bulked throughout California and on pallets anywhere requested. Monsoon Season Boulders is a very hard rock material that ranges from blue green to blue gray with patches of white coloring the rock. There are veins of rock in this quarry with strong iron and other mineral veins running through the rock. This rock is covered in full or in patches with a mineral patina over the dark gray rock color tones.