Schillerize

The felspar is strikingly schillerized along from one to five planes of the crystal.

Thus some pyroxenic minerals are seen to contain numerous enclosures in the form of thin plates and rods arranged along parallel planes in the crystals, these, when the crystals are looked at in certain positions, give it a peculiar semi-metallic lustre or "chatoyant" character, which is termed schillerization, thus diallage and hypersthene are shown to be schillerized forms of augite and enstatite, and Professor Judd observes that "the production of schillerized condition is related to the depth at which the crystals have originally existed; schillerized forms being found only in deep-seated intrusive masses.

The rocks consist of weakly pleoehroic schillerized hypersthene, occurring as anhedral crystals up to a centimetre in length, schillerized diallage, and anhedral crystals of olivine several millimetres long, the fractures in which contain iron ore.

In outcrop the large elongate feldspars, which schillerize a brilliant sky blue when wet, are consistently oriented between 330 and 360 degrees.