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).
Schist is a medium-grade metamorphic rock with medium to large, flat, sheet-like grains in a preferred orientation (nearby grains are roughly parallel). It is defined by having more than 50% platy and elongated minerals, often finely interleaved with quartz and feldspar.or example, many metamorphic limestones, marbles, and calc-schists, with crystalline dolomites, contain silicate minerals such as mica, tremolite, diopside, scapolite, quartz and feldspar. They are derived from calcareous sediments of different degrees of purity.