This is the gemstone part of
https://www.shapeways.com/product/8PQUE5YSR/dmc-5-nero-pendant. Pendant was designed as Fanart and is hosted for free on Myminifactory.com for personal non commercial usage. Files hosted on Shapeways for those without a printer looking to get a print of the pendant for cosplay or everyday wear.
To replicate a gemstone effect, reccomend taking a mold of the gemstone print and casting in a clear or semi colored resin.