The obverse of the coin at the top the emblem of the USSR of the sample of 1956 (15 bands of tape around the number of the Union republics, the lower coil larger than the other). Under the emblem of a large letter "СССР" yet below is the value: a large figure "3" under it the word "РУБЛЯ" At the very bottom near Kant is the year of issue "1990". In the bottom left, under the horizontal line in the two lines marked metal, fineness and weight of pure silver - "Ag 900 to 31.1" on the right side under the same trait located at the same level, is a mark of the Leningrad mint (stylized letters "ЛМД".
On the reverse in the centre is a embossed image, dedicated to the expedition of J. cook: in the foreground the meeting of cook and his team with the residents of Alaska, on the back of the ships in the Harbor against a mountain landscape. On the left schematically shows the astrolabe (base unit of sailors of that era), the year of the opening "1778". Upstairs along the edge to the handwritten font in a semicircle the inscription: "250 ЛЕТ ОТКРЫТИЯ РУССКОЙ АМЕРИКИ" at the bottom in the same font, but more finely - "ЭКСПЕДИЦИЯ Д. КУКА В РУССКУЮ АМЕРИКУ"(both labels separated by dots).
On the front and back parts of the coin along the circumference has a raised rim.
Photo source: www.coins-market.ru
James cook - English Explorer of the eighteenth century, made three round the world expeditions, completing an era of Great geographical discoveries. Explored the territory of Alaska, which in Russia was called Russian America. In 1869, Alaska sold to US for 7.2 million dollars. Some people mistakenly think that Alaska was sold only 100 years, in fact in the contract of transfer of land says nothing about this.