Essexite

Essexit is a dark, gabbroides rock formed from volcanic processes.

• 3.1 Notes and references

Description of rock and mineral composition

Essexit occurs as mesotypes, melanokrates and sodium- rich plutonic rock. The rock was named after the Essex County in the U.S. state of Massachusetts and is the gabbro similar.

However, in contrast to the gabbro Essexit also contains sodium-rich alkali feldspar, which is often found as a hem to plagioclase. In addition mainly occurs diopsidischer augite. Nebengemengteile are sodium amphibole, biotite and serpentinized olivine.

History

The first scientific description comes from John Henry Sears (1843-1910) from the year 1891. Sears was curator ( 1892-1910 ) of the areas of mineralogy, geology and botany at the Peabody Museum in Salem, Massachusetts.

Occurrence

Essexit is known from countless places. In Germany Essexit occurs at the Kaiser chair or in the Seven Mountains. Other occurrences are known for example from Russia of the Taimyr Peninsula, the area of Kuznetsk Minusinsk, in Tuva and on the Kamchatka Peninsula, in the area of the Omolon, Sakhalin and from Primorye. In addition Essexit comes at Mount Royal near Montreal in Canada before, in Norway near Oslo, in Roztoky in the Bohemian Central Mountains in the Czech Republic or in Carclout in Ayrshire, Scotland. Also, the Deccan Traps in the Indian province of Kathiawar leads Essexite.