It may well be a kind of broach, the second picture shows it to be like a flattened ring, in a pretty bad state, so either it is very old and has been bashed over a long period of time into its current shape, or that it was a stolen item that someone has unsuccessfully attempted to melt down.
Certainly take it to be looked at by an expert, but in the mean time you could check it for hallmarks, engravings see if it is magnetic, how soft and malleable the metal is, or if there are brush strokes suggesting it has been painted. The patterns could be useful in revealing a style of design, so have a look on the internet for other similar items to compare yours against. Try not to damage the item, and certainly do not try and clean or wash it, put it into a box and keep it somewhere safe.
The stones to me look as they could be a polished rose quartz jem, and the darker one polished obsidian, both of which are common substances throughout Europe. Some of the scratches on the surface do not though make them look that authentic, so they may be a plastic or resin copy, note also in picture two there is what looks like a stone missing to the left, look closely at this area as it may give some clues as to how the stone was fixed to the item and if there is any material left, i.e. shards of gemstone or bits of plastic. A real stone would be much colder to the touch than a plastic replica and may change color with heat depending on the type.
Generally just make sure that you record the place that you found it, preferably a grid reference, when you found it, and the full circumstances, then the wider area can be scanned for known archaeological sites and your item compared to other finds in the area. Also keep your photographs safe as proof of your custody of the item, if it is worth anything you may be entitled to the sum of the value of the metals and the stones, or a reward for finding it and handing it in, if this is the case then the landowner upon whose land you found the item is usually entitled to half of any payout.
Keep us posted,
...love is just a camouflage for what resembles rage again...