This lode is a belt of quartz, 10,000 feet long and several hundred wide, and is a contact vein between diorite and diabase.
Quartz porphyry, diabase and diorite appear in the Ardennes.
One, a complete specimen composed of a diabase, was shaped by pecking followed by grinding.
The minerals of diabase are the same as those of dolerite, viz.
The materials filling these vents consist of agglomerate charged with blocks of diabase, sandstone, flagstone and limestone.
In Arizona chrysotile is found in veins in cherty limestone, associated with diabase intrusives.
The sandstone and trap are of the Triassic Period, and the trap of this vicinity is more particularly classified as diabase.
At St Andreasberg in the Harz it occurs both in diabase and in the veins of silver ore.
None the less, its origin as diabase can definitely be asserted of the whole mass.
Curaao consists of eruptive rocks, chiefly diorite and diabase, and is surrounded by coral reefs.