Definition

Noun: A hard, dark grey to black mineral that is a hydrated oxide of manganese and barium, often occurring in botryoidal (grape-like) or stalactitic masses. It is an important ore of manganese.

Usage

Psilomelane is used primarily in geological and mineralogical contexts to identify a specific manganese-bearing mineral. It is also relevant in industrial contexts as a source of manganese.

Examples

• The geologist identified the black, lustrous mass as psilomelane.
• Psilomelane is often found in association with other manganese oxides like pyrolusite.
• This deposit contains significant quantities of psilomelane, making it economically viable for manganese extraction.

Advanced Usage

• In mineral classification: Psilomelane is not a single mineral with a definite chemical formula but rather a mixture or a general term for hard, massive manganese oxides. Modern mineralogy often reclassifies such material.
  • Example: The specimen was historically labeled psilomelane, but X-ray diffraction revealed it to be predominantly romanechite.

Variants and Related Words

• Romanechite (n): A specific mineral species that much of what was historically called psilomelane is now identified as. It has a defined crystal structure and formula (Ba, H2O)2(Mn4+, Mn3+)5O10.

Synonyms

• Black manganese ore (general industrial term)
• Hard manganese ore (descriptive term distinguishing it from softer oxides like pyrolusite)

Notes on Different Meanings

The term "psilomelane" has a specific, technical meaning in geology and mineralogy. It does not have common idiomatic, phrasal verb, or colloquial uses. Its usage is confined to scientific and industrial descriptions.

Noun

1. a mineral consisting of hydrated basic oxide of manganese and barium; a source of manganese