The90 Launches The Gem, a Smart Necklace That Tracks Personal UV Exposure

Overview

• The90 has begun selling The Gem on its website with an early-adopter price of $199 and a planned regular price of $299, and the company says orders will ship in June.
• The Gem is a small pendant that the company says contains on-board UVA and UVB optical sensors and streams real-time readings to a paired phone using Bluetooth Low Energy.
• Company-published specs list roughly seven days of battery life per charge, about two hours to recharge, splash resistance, and a compact jewelry form factor available in gold or silver finishes.
• The companion app links live UV data to a user skin profile that includes Fitzpatrick typing to provide sunscreen-decay modeling, reapplication alerts, and recommended sunlight windows.
• The product is led by founder Stacy Salvi, a former Fitbit executive, and backed by entrepreneurs including Lauryn Bosstick, but independent validation of sensor accuracy and long-term real-world performance has not yet been reported.