This probably started life with a piece of glass where the malachite now is and a locket back, to contain a lock of the loved-one's hair. Nowadays most of us would prefer it in its present state, with a dramatic piece of malachite in place of the glass.
Unmarked, as was quite a lot of Victorian sentimental jewellery, which was made by a jeweller directly commissioned by the original owner, it tests as 15ct gold. It measures about 1.1" in width, and has a tiny hinged loop at the back to take a safety chain.
One of the seed-pearls is cracked, as can be seen on the magnified photo, but that is not surprising, given the age of the piece. An attractive and unusual brooch.
Presented in a handsome velvet-lined box.
Price includes packaging, insurance and Air Mail shipping anywhere in the world.