Medny Island, Commander Islands (Komandorskie Islands), Kamchatka Krai, Russiai

Regional Level Types
Medny Island	Island
Commander Islands (Komandorskie Islands)	Group of Islands
Kamchatka Krai	Krai
Russia	Country

The island, which is 56 km long and between 5 and 7 km wide, received its name from native copper (медь in Russian), found here in 1745 by the entrepreneur Yemelyan Basov, during his second of four expeditions to the Commander Islands.

The island is the type locality for stellerite (Morozewicz, 1909), a zeolite of the stilbite subgroup.

Józef Morozewicz (27 March 1865 – 12 June 1941) was a Polish mineralogist and petrologist, the founder and first director of the National Geological Institute (Państwowy Instytut Geologiczny) in Warsaw. In the years 1895-1904 he worked at the Geological Committee in St. Petersburg, russian geological organisation (also know as Geolkom), a part of The Ministry of State Property of the Russian Empire. In 1903, by the decision of the Mining Institute (that later became Saint Petersburg Mining University), Morozewicz became the head of the expedition to the Commander Islands. Together with the mining engineer Leonid Konstantinovich Konyushevsky, they arrived on the Commander Islands on June 24, 1903 and remained there until the beginning of October, investigating for over three months, the two largest islands of the archipelago - Bering Island and Medny (Copper) Island - Russian: Остров Беринга, Остров Медный. A large amount of rocks and minerals was collected, and the alleged ore deposits about which legends existed, were investigated. Geological maps of both islands were developed; copper ore reserve received a negative assessment and assumptions about the wealth of islands with gold have not been confirmed at all. The results of the expedition formed the basis of two scientific papers by Morozewicz - monographs "Остров Медный" (1912 in Russian) and "Komandory" (1925, Warsaw, in Polish). In 1909 (printed in 1910), he published in Cracow in the scientific journal information about the discovery of a new zeolitic mineral (in German) on the Medny (Copper) Island , which he named stellerite in a honour of Georg Wilhelm Steller (Stöller), a German physician, naturalist and explorer, who took part in the second expedition to Kamchatka led by Vitus Bering.
Below translation of the fragments:

"In the north-western part of the island, within the mountainous ridge, whose durable rocks rise to a height of 450 m above sea level. Gloomy, inhospitable hills are built mainly from a not stratificated, fragile, filthy-greenish diabase tuff, with many diabase and melaphyre veins. The tuff structure sometimes resembles coarse breccia. Against a background of the darker, fine-grained rock mass, there are visible grains of calcite and olivaceous augite. Here and there, there are irregular vugs, veins and geodes partially or completely filled with a whole range of secondary minerals. Mostly calcite and various generations of quartz, then zeolites among which the main role is played by analcime, the youngest in this paragenesis seems to be native copper. The new zeolitic mineral (stellerite) occurs on a high ridge of diabase tuffs, cut by several ascending.wall-like melaphyre veins. Based on the Stejneger's map*, the accurate point was determined, according to the parameters:
ρ = 54 ° 51'30 ”
λ = 167 ° 31
In smalls, baggy nests with analcime crystals, especially here abundant native copper. Less frequent more regular veins with a thickness of 2 to 3 cm which, due to their pale pink content, sharply contrast with the dark background of the tuff. It is mainly a flesh pink zeolite, less frequently slightly etched calcite and rarely native copper in the form of wires, stuck in the middle of the veins. On the fracture, these veins show a beautiful leafy-laminated structure, in which individual plates sometimes completely fill the vein cross section. In some cases, crystals were also found.

Forms of crystals.
Rare, unilaterally developed groups of crystals consist of tabular individuals, differently orientated and inclined, about 5 mm long, 3-4 mm wide and 1-2 mm thick. Their external habitus is reminiscent of some of the heulandite appearance, especially on some surfaces that show perfect cleavage.



The crystal points are always sharpened with the four faces of the pyramids, which in turn resembles the well-developed twins of the desmin (today stilbite). However accurate optical studies have shown, that these are not monoclinic crystals, but rhombic and homogeneous monocrystals."

* - Leonhard Stejneger 1896 - The Russian Fur-Seal Islands, Washington

Location determined on the basis of the data from this work and the map of Leonhard Stejneger. In 1975 in honor of Morozewicz, a new rare sulfide mineral was named morozeviczite.

K.Andrzejewski - March 2019

Fossils

This region is too big or complex to display the fossil list, try looking at smaller subregions.

References

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Medny_Island
Wikidata ID:	Q251315
GeoNames ID:	2123363