Heh, I've been itching to post in this thread, but I didn't want to ruin
bondoking's Secret Santa surprise 
I made him a very rough replica of a Bloodstone. Obviously mine isn't quite screen accurate, but I found a few things during research for it I thought I'd share.
View attachment 1652243
The chain appears to be this
RCH Hardware CH-BR47-W Brass Chandelier Chain, which oddly seemed to be cheaper through Walmart than their direct site.
And I cast the stone with these
prefab silicone gemstone molds using an epoxy resin and some resin dye with the intial intention of embedding lights and carving/polishing the stone (ran out of time - my pics are just lit from behind with fairy lights).
View attachment 1652245
I had just been looking for something approximately the same size and shape, but looking at the finished gem, I think I MAY have accidentally stumbled on what they used as the base for the actual prop, as the outline of the stone is very similar. I'm going to eventually make one for myself, so we'll see how close I can Dremel the stone to match.
View attachment 1652244
View attachment 1652246
Also, I didn't get to add the charms and religious medals to the chain, but the vial appears to be some sort of cremation urn necklace pendant. Haven't tracked down one with the leaf design, but plenty out there similar that could maybe be adapted or serve as a placeholder.
View attachment 1652319
Anyway, just wanted to share, as I was a big fan of the Marvel special and was also hoping for a run of it from Marvel/Disney!