Quartz on Limonite Boxwork
This is a particularly interesting type of mineralogical occurrence, as there were 3 different minerals involved in forming the final result. First there was a sulfide mineral which over time completely dissolved, leaving hollow honeycomb-like cavities known as ‘boxwork’. Within this hollow boxwork structure, thin interconnecting sheets of limonite formed on surfaces. At a later date transparent quartz formed a druse coating.