Janggunite is a rare

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

oxide mineral with the chemical formula . It was first described in 1975 for an occurrence in the Janggun mine,

Bonghwa Bonghwa County (''Bonghwa-gun'') is a county in North Gyeongsang Province, South Korea. It lies inland, at the northern edge of the province, and borders Gangwon province to the north. To the east it is bounded by Yeongyang and Uljin counties, ...

-gun,

Gyeongsangbuk-do North Gyeongsang Province ( ko, 경상북도, translit=Gyeongsangbuk-do, ) is a province in eastern South Korea. The province was formed in 1896 from the northern half of the former Gyeongsang province, and remained a province of Korea until the ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...

and named for the locality.

References

Oxide minerals Manganese minerals Orthorhombic minerals Minerals in space group 53 {{oxide-mineral-stub