Rose Calcite Trilobite The spectacular display of colors

The spectacular display of colors these specimens display can be formed by two different geological processes: the oxidation of pyrite causing ultra-thin layers of iron oxide to form on the surface

resulting from the oxidation of its copper and sulfide components

and when exposed to the elements over a long period of time can change into the closely related malachite

from the Upper Silurian age

pyrite is an abundant sulfide mineral that despite some similarities can easily be distinguished from actual gold by its crystal form (typically cuboidal) and being much harder whereas gold is soft and malleable

Rose Calcite Trilobite The spectacular display of colors