Mineralogy
Mineralogy is the systematic study of minerals, often including petrology - the study of rocks. It focuses on a compound's physical and chemical properties to group minerals together.
Minerals are naturally occurring, solid chemical compounds, identified by their crystalline structures and vibrant colours! Rocks are formed through two or more minerals, compounded through geological processes.
Crystal structures form lattices of ions, or charged particles. These are called cations (positively charged) and anions (negatively charged). The cation is often a metal, which is interchangeable, and the anion forms the base structure that the mineral is often grouped. Different bonding leads to different mineral groups, some of which we have on display in the Museum!
Oxides
Sulphides
Sulphides
Oxides are formed when an oxide anion bonds to the metal cation.
Examples include hematite (Staffordshire) and ironstone (Cumbria).
Sulphides
Sulphides
Sulphides
Sulphides form from a central silicon cation, bonded to four oxide anions.
Examples include quartz (Derbyshire) and opal (Cornwall).
Silicates
Sulphides
Silicates
Silicates form with sulphide or disulphide as the major anions. This is the most important group of ores, and supplies a wide variety of metals.
Examples include pyrite (Yorkshire Coast) and bournonite (Cornwall).