I just bought them, but didn't think to ask the salesman what they were. Gemstone changes from brown (artificial light) to pink (natural light). The larger necklace was $250 : r/whatsthisrock
Real Zultanite Big Pieces Gemstone Color Changing Crystal Cut Form Changes More Than 7 Different Color - Etsy UK
ZULTANITE — Provenance Gems
ZULTANITE — Provenance Gems
4.45 Ct Natural Round Cut Zultanite Color Changing Turkish Best Loose Gemstone | eBay
EGL Certified 14.45 Ct Natural Cushion Zultanite Color Changing Turkish Best Gem | eBay
Zultanite Color Change Necklace-Turkish Handmade Zultanite Necklace- Zultanite Gemstone Jewelry-Women Color Change Jewerly -Silver Jewelry Pendant-Color Change Pendant-Necklace for Women-Gift for Her : Amazon.co.uk: Fashion