Emerald has been used as precious gemstone for thousands of years, almost through human's civilization. "Benefit by" the extremely hard to catch the right color rather than a blue cast, the only way to pry into this vivid green* (Muzo color) is to look at it in-person. It's also one of my first gem crystal collections (also in my core collection) that was purchased in 2018 when I was 17.

This 2.5cm piece represents the highest level of color from Muzo mine, Columbia. Although most of emerald deposits are found in association with igneous rocks, Muzo mine is an exception of no evidence of any igneous activities. The interesting thing is to thank to Lower Cretaceous black shale and limestone, which are Marine/lake-type sedimentary rocks. When hydrothermal brine transported evaporitic sulphate, will be thermochemically reduced and generate sulfur that reacted with organic matter in the shales to release trapped chromium, vanadium and beryllium, which in turn enabled emerald formation.

Photo Credit:Jeff Scovil