The US Coast Guardâs largest patrol cutters are the 418 foot, 4,500 ton full load Bertholf Class National Security Cutters. The illustration that accompanies the story of the four new 5,000 ton cutters shows a ship, in many ways similar to the National Security Cutter. It appears there is a medium caliber gun on the bow.
Amphibolite is a rock composed mostly of amphibole minerals. Usually it's a hornblende schist like this as hornblende is the commonest amphibole.(more below). Amphibolite forms when basaltic rock is subjected to higher temperatures (550750Â°C) and slightly greater pressure range than that which yields greenschist.mphibolite is a rock composed mostly of amphibole minerals. Usually it's a hornblende schist like this as hornblende is the commonest amphibole. (more below).
Amphibole mineralsâ defining characteristics are their dark color, hardness and well-developed cleavage. These usually serve to distinguish them from most other common rock-forming minerals with the exception of the pyroxene mineral group.mphibole comes from the Greek word amfibolos, which means âambiguousâ or âdoubtfulâ. Ambiguity also surrounds the older name for part of the mineral group. Although it is no longer used as a mineral name, the most common rock-forming amphiboles were once called âHornblendeâ.