Grossular garnet is perhaps the least-known of the gem garnets, and yet it deserves broader recognition, as it can be fashioned into gorgeous gemstones. The only commonly-known grossular garnets are the green varieties–deep green tsavorite and lighter green Merelani Mint garnet. Grossular garnet can actually be found in a broad range of colors, from reds to oranges, yellows and greens. Indeed, some of the rarest of all gem garnets are colorless to nearly colorless grossulars referred to as “leucogarnets.”
This particular grossular garnet comes from the famed Jeffrey Mine in Asbestos, Quebec, Canada. The mine was a large open-pit asbestos mine that closed in 2001. While it was operating, collectors were able to find pockets of grossular garnet–including bright green tsavorites–and several other minerals valued by collectors. Most of the garnets were smaller, although they were typically very gemmy. This is the largest gem grossular I have seen from the Jeffrey Mine. I cut this large gem from a damaged and broken crystal that started out at just over 50 carats. After removing the included areas I was left with a preform of 23 carats.
The finished gem is 11.28 carats and measures 14.0 x 11.2 x 9.7 mm. It is eye clean at a normal viewing distance, although you can see some veils of small bubbles if you look for them closely. I faceted this gem in a variation of my custom “Helena” brilliant oval design, and its quite brilliant in the hand. While the term can be over-used, this truly is a gem that is “museum worthy” given large size for this locale.