# Reviewing the Gem UV-Tracking Necklace and Its Health Insights A wearable device reveals how sunlight exposure impacts health beyond just skin aging. - **Source:** [The Verge](https://www.theverge.com) - **Published:** 2026-11-07 - **Topic:** [technology](https://brifing.si/c/technology) - **Original article:** - **On Brifing:** https://brifing.si/s/89d997a7-88b7-4f0a-bfc3-7dac57b72aad ## Wearable UV Monitoring Technology The Gem is a $249 titanium necklace designed to track UVA and UVB radiation exposure. Unlike standard weather forecasts, this wearable uses a dedicated sensor to provide personalized data. It aims to help users balance the benefits of sunlight, such as vitamin D production, against the risks of skin damage. ## Unexpected Health Discovery During an outdoor event in August, the device alerted the user to high UV levels despite being under a patio umbrella. This notification helped the user realize that shade does not guarantee protection from radiation. The incident prompted an investigation into heat sensitivity linked to the user's existing medical prescriptions. ## Device Design and Functionality The pendant features a discreet, jewelry-like aesthetic available in titanium, gold, or silver finishes. It offers a one-week battery life and recharges via a dedicated dock. The manufacturer plans to expand the ecosystem with hat clips and bag tags, providing more versatile options for users who prefer not to wear necklaces. ## Mobile App Integration The companion app serves as the primary interface, offering graphs and personalized skincare advice based on user profiles. It calculates metrics like cumulative UVA exposure and potential vitamin D synthesis. However, the app must remain active in the background to ensure continuous tracking, which can be a limitation for iPhone users. ## Sun Score and Metrics The app provides a daily Sun Score, aiming for a target of 90 to balance health benefits and risks. While the score offers a high-level overview, the individual UVA and UVB readings proved more insightful for the user. These metrics help identify exposure patterns that are otherwise invisible to the naked eye. ## Accuracy and Data Fluctuations The sensor responds quickly to environmental changes, including moving between sunlight and indoor spaces near windows. However, the app's countdowns for vitamin D production and sunburn risk showed significant fluctuations during testing. These dramatic changes made the specific time estimates less reliable than the broader trends provided by the device. ## Rethinking Sun Exposure Testing the device revealed that the user often experienced extremes: either too little sun to meet vitamin D targets or enough to risk overexposure. This shifted the user's perspective from purely aesthetic concerns about aging to a more holistic understanding of how sunlight impacts overall physical well-being and daily health. ## Value and Practical Utility At a $249 price point without subscription fees, the Gem is a premium investment. While the cost may be difficult to justify for those who spend most of their time indoors, it offers significant value for outdoor enthusiasts. It successfully encourages more mindful habits regarding sun protection and daily health management. ## Sources covering this story - https://www.theverge.com/tech/1023230/the90-gem-necklace-hands-on-impressions — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._