Whisper Briolette

Usage affixed to armor or to an outfit if a character has no armor

This teardrop-shaped gemstone has triangular facets and looks suitable for fancy attire, although close inspection shows that it's hollow. When it's activated, you can instantly impart up to 1 minute of speech (roughly 150 words) telepathically to any creatures you choose within 100 feet. You can impart this instantaneous telepathic message to creatures that you perceive and creatures Hidden to you, but you can't do so to Undetected creatures. Once used, the whisper briolette becomes unusable and subtly vanishes within the next few minutes, rather than crumbling to dust.