The90 Gem UV tracking necklace is a wearable device that measures personal sunlight exposure throughout the day. Unlike weather apps that provide regional UV forecasts, the Gem uses built-in sensors to monitor UVA and UVB radiation near the wearer’s body.
The jewelry-style device pairs with a smartphone app that estimates sunburn risk, cumulative UV exposure and vitamin D-related sunlight exposure. It offers a different approach to sun monitoring, although independent testing has raised questions about its accuracy and tracking reliability.
How The90 Gem UV Tracking Necklace Works
The Gem uses a photonic sensor to measure UVA and UVB radiation separately. UVA contributes to skin aging, while UVB is strongly associated with sunburn. Both can damage the skin through prolonged exposure.
According to The90’s official product information, the sensor transmits readings through Bluetooth to a companion app. Users create a personalized profile using their skin type, sunscreen habits and other relevant information.
The app displays real-time UV intensity, accumulated exposure and an estimated countdown to sunburn. It also provides sunscreen reminders and a Sun Score summarizing daily exposure.
These measurements can reveal differences between regional UV forecasts and what an individual experiences. Shade, reflected sunlight, and nearby surfaces can affect exposure even when direct sunlight is limited.
Real-World Testing Reveals Useful Insights
Independent hands-on testing found that the Gem responded to changing sunlight conditions. Readings varied when the wearer moved between outdoor locations, shaded areas and indoor environments.
The device also revealed unexpectedly low UVB exposure during ordinary routines. Conversely, it recorded significant radiation in shaded outdoor settings, demonstrating why an umbrella does not necessarily eliminate UV exposure.
However, estimated sunburn countdowns sometimes changed dramatically between readings. The reviewer could not independently verify thesensor’ss accuracy, making its broader exposure trends more useful than precise predictions.
Smartphone Dependence Limits Continuous Tracking
One notable limitation involves the companion application. During testing, tracking stopped when the iPhone app was fully closed, potentially leaving gaps in daily exposure records.
This behavior reduces the usefulness of a device intended for continuous monitoring. Users may need to keep the application running to maintain complete exposure histories.
The Gem also estimates vitamin D-related exposure rather than directly measuring vitamin D levels. Its calculations should not be treated as medical assessments or substitutes for established sun protection guidance.
Design, Battery Life and Price
The90 designed the Gem to resemble conventional jewelry rather than a fitness tracker. Its removable sensor fits inside a pendant available in gold and silver finishes.
The company advertises more than seven days of battery life and charging times under two hours. The necklace is splash-resistant but is not intended for swimming or prolonged immersion.
The manufacturer currently lists the device at $299, with no subscription required for its companion app. It includes a 30-day return policy and a one-year warranty.
Is The90 Gem Worth Considering?
The90 Gem offers a convenient way to observe personal UV exposure without wearing a conventional smartwatch. Its jewelry design and weeklong battery life make it suitable for everyday use.
However, its relatively high price, app dependence and unverified precision limit its appeal. People seeking exact sunburn predictions should be particularly cautious about relying on its estimates.
The Gem is most useful as an awareness tool for recognizing sunlight exposure patterns. It does not replace sunscreen, protective clothing or professional medical advice.
