They are soft and lustrous, with a peculiarly smooth feel, and though often confounded with mica-schists may be distinguished by their richness in magnesia; many of them contain tremolite or actinolite; others have residual grains of olivine or augite; and here also every gradation can be found between the unmodified igneous types and the perfectly metamorphic schists.
From the richness and mellowness of the soil potatoes and all taproots reach a great size.
The comparative richness of proteaceous plants in Western Australia and South Africa first suggested a common source for these primitive types.
It may be safely deemed the most peculiar area of the earth's surface, while from the richness and multifariousness of its animal, and especially of its ornithic population, New Zealand cannot be 'compared with it.
The richness and variety of decoration increased from the 14th century onwards.