Spire shaped mineralisations of iron (Fe) and manganese (Mn) oxides in a thin slice of agate (chalcedony), photographed in transient light. The minerals formed are such as goethite or hematite in the case of iron and pyrolusite in the case of manganese. The mechanisms of precipitation of these minerals in agate are complex. The precipitates can have various forms, with spires and dendrites most common. Highly professional cutting and polishing of these agates is an art that accounts for attractive visual scenery. Actual width of this sample is a mere 25 mm. Provenance is volcanic deposits in Espumoso, Minas Gerais, Brazil.