This is the name of several towns, stations and mountains found in Japan.
The first one (黄金) is used on a town which is part of Yokohama (along with its station), 2 stations that are located in Nagoya in Aichi prefecture and southern Hokkaidō and 2 mountains that are located in western Hokkaidō and Hiroshima city.
The second one (小金) is used on an area of Matsudo in western Chiba prefecture, which borders the Tōkyō metropolitan area.
The kanji used are 黄 (ou, kou, ki, ko-) meaning "yellow", 小 (shou, o-, ko-, sa-, chii.sai) meaning "little, small" and 金 (kin, kon, gon, kana-, kane, -gane) meaning "gold."
Kogane is also used as a feminine given name and a surname.