Antique (more than 170 years old), Envelope / Love Letter / “poison” ring in the form of an envelope with a hidden compartment covered with secure and tight hinged lid decorated with faceted Garnet. The lid close tightly with a click.
Rings like this have been used throughout history to carry perfume, locks of hair, devotional relics, messages and other keepsakes, so they have also been known by other names. Super romantic.
Made in Sweden in the first half of the 19th century, indistinct stamps probably Peter Magnus Wallengren, Ystad, size about 18 cf. 57, weight about 1.8 grams.
Re-sizing is possible.