Spinel, Forsterite

This specimen features a fairly large, complete black octahedral spinel crystal, accompanied by forsterite and set in a bit of a left over calcite matrix. Due to its size the spinel exhibits many successive, stacked layers of parallel crystal growth, a characteristic feature of this mineral. The specimen originates from the Parker Mine, a well-known locality in Quebec, Canada. Initially opened in the early 1900s for mica mining, the Parker Mine is renowned for producing exceptionally large and well-formed crystals, particularly within its carbonate vein-dyke systems. The area, composed of regionally metamorphosed Precambrian sediments, has yielded notable specimens, including euhedral forsterite crystals up to 30 cm and ferroan spinel crystals up to 6 cm. This specimen is an excellent example of the fine mineralogical diversity found within the Parker Mine’s unique geological environment.

*Note: Since photographing the specimen I put it in a bit of vinegar and it now has less calcite on it than originally pictured. Looks better in-hand than the pictures.