Quest or activity
Silver Brooch is obtained during a confirmed quest source.
Follow the linked quest. The source confirms acquisition during the quest, but does not identify a specific objective or say it is awarded when the whole quest ends.
VALUABLE
Yes — you can safely sell it.
It sells for 95, and another copy can be obtained if you need one later.
The most direct way to get Silver Brooch is through A Deal with the Devil. Possible loot is not guaranteed if you need a specific copy.
Owning silver is illegal in Vale Sangora – which makes it as valuable as it is dangerous.

Quest or activity
Follow the linked quest. The source confirms acquisition during the quest, but does not identify a specific objective or say it is awarded when the whole quest ends.
Possible loot — not guaranteed
This is not a guaranteed drop. Prefer a mapped pickup, quest, or merchant listing if you are hunting a specific copy.
Follow the mapped pickup or quest source first; it is the most predictable route currently listed.
The most direct way to get Silver Brooch is through A Deal with the Devil. Possible loot is not guaranteed if you need a specific copy.
Listed buy price is 575 Denarii.
QUICK ANSWER
Sellable valuable
ITEM DECISION GUIDE
Yes — you can safely sell it.
It sells for 95, and another copy can be obtained if you need one later.
WHAT IS IT USED FOR?
That does not mean it has no use later in the game.
See what it is used for →CAN I SAFELY SELL IT?
It sells for 95, and another copy can be obtained if you need one later.
CAN I GET ANOTHER?
Use the confirmed quest, shop, crafting, or fixed pickup route below.
KNOWN USES
No known quest, crafting, or dialogue use has been found yet. A sell value of 95 is not a reason to get rid of it.