The famous German scientist Philipp Franz von Siebold (1796–1866) had the chance to work from 1823 to 1830 as a resident physician on the Dutch trading post Dejima in the Japanese city Nagasaki. During this time, when Japan was still virtually closed for western scientists, he was able to study the geography, geology, zoology and botany of this highly interesting country. After his return to the Netherlands, he wrote three parts of his fundamental work Nippon—Archiv zur Beschreibung von Japan (1832–1858, 1879), most of which appeared during his lifetime. In contrast to Fauna Japonica (1833–1850) and Flora Japonica (1835–1870), the geoscience part De Mineralogia Japonica remained unpublished until 2016, when Tokuhei Tagai and Lothar Schröpfer edited an English translation together with the facsimile of the text, actually handwritten by Siebold’s assistant Heinrich Bürger (1804–1858). Beyond doubt, De Mineralogia Japonica gives the first insight in the geology of Japan islands, its minerals, rocks and mineral deposits during a time, when the Japanese empire gradually started to open up to western science and, on the other hand, the violent discussion between neptunists and plutonists was still going on in Europe. A highly interesting aspect of Bürger's text is the detailed description of traditional methods for mining copper ore as well as melting and refining of copper used during this time in Japan.
In this mineral class, oxygen forms compounds with one, two or more metals. In contrast to the sulfides, the crystal structures of oxides display predominantly ionic bonds, in part with transition to atomic bonding.
This class of minerals comprises a particularly large variety of different mineral species because of a wide range in ionic substitution possibilities.