Rare Gutta Purcha Rose Gold Mourning Brooch

This is a quite rare Victorian Gutta Purcha brooch combined with gold.
Because I doubted whether this brochure is made from Gutta Purcha or Vulcanite I had to testand TASTE it first and it taste salty. So I came to the conclusion it's made of Gutta Purcha.
Gutta Purcha is light sensitive and has a tendency to turn brown (as sthis brooch cleary shows) with exposure to light (and oxygen) over the years. Most of the Gutta Purcha jewelry seen today is brown and not black like it was originally. The color is a clue to its material nature. It's a rubber-like gum derived from the resin of trees from Southeast Asia, especially Malaysia; highly flexible yet durable, it began to be used in the 1840s for jewelry, especially mourning jewelry the latter 19th century, as a more reasonable substitute for jet. Gutta Purcha is also molded, not carved, so there won’t be any visible tool marks on the piece. Since it’s basically a rubber-like material, it will smell like rubber when it’s rubbed briskly on fabric. And the most effective way to tell if your jewelry is Gutta purcha- TASTE IT. Seriously. Please wash it before and after tasting it and in fact, taste it at your own risk. But if you choose to taste it, it will taste salty. If it doesn’t taste salty, it’s not Gutta Purcha.