JFD07AN5: Reocín Marcasite is dangerous because it tends to decompose relatively easily, especially in humid climates like Barcelona's. For some reason this piece has remained 'healthy' despite the many years it has resided in my collection. I do not know whether the Dolomite, pinker than usual in Reocín, has anything to do with its good preservation, but the fact is that here it is, resisting the passage of time quite nicely.
Reocín Mine, Reocín, Comarca Saja-Nansa, Cantabria  Spain (±1985)

Specimen size: 5.4 × 4.3 × 3.7 cm = 2.13” × 1.69” × 1.46”

Main crystal size: 0.6 × 0.5 cm = 0.24”