The White Cliffs of Iturup Island

Stretching from Hokkaido, Japan to Kamchatka, Russia, separating the Sea of Okhotsk from the north Pacific Ocean, are a string of volcanic islands called Kuril Islands. The archipelago belongs to Russia, but Japan claims the four southernmost islands, including the two largest ones—Iturup and Kunashir.

Iturup was Japanese territory until the end of the Second World War in 1945, when Soviet forces took possession of all the Kurils and forced out Japanese residents. Japan has been trying to regain the islands ever since.

White Cliffs of Iturup Island

Image credit: Sergey Dolya

Iturup island is very beautiful with volcanic massifs and mountain ridges. About a dozen calc-alkaline volcanoes running along the length of the elongated island form the backbone of the island. The shores of the island are high and abrupt and is marked by white pumice cliffs and black hexagonal pillars. The island also contains some high waterfalls.

White Cliffs of Iturup Island

Image credit: Valerii_M/Shutterstock.com

Iturup island is the source of a very rare mineral called rheniite, of the element rhenium. Rhenium is one of the rarest elements in the Earth's crust with an average concentration of 1 parts per billion, or lower. It usually occurs in other mineral ores such molybdenite. Iturup island is the only place where this mineral occurs in its pure form. The mineral is emitted in the gaseous state from fumaroles on Kudriavy volcano and is extracted by condensation. Kudriavy discharges up to 20–60 kg rhenium per year mostly in the form of rhenium disulfide. Named rheniite, this rare mineral fetches high prices in the market. Rhenium is used in the combustion chambers, turbine blades, and exhaust nozzles of jet engines. Rhenium is also used as a catalyst in industries for hydrogenation and isomerization, and is used for example in catalytic reforming of naphtha for use in gasoline.

White Cliffs of Iturup Island