The modular 'Gem' pendant aims to go one better than your smartphone's UV index
Skin health company The90 has officially entered the wearable tech arena with the launch of its debut hardware, the Gem UV sensor.
Positioned as a piece of high-end smart jewelry rather than a traditional fitness or health tracker, the $299 modular pendant is designed to help women measure real-time UVA and UVB exposure, analyze their cumulative sun load, and make better-informed decisions about daily skin protection.
Instead of relying on weather app information, which generally provides broad, location-based estimates, the Gem focuses on a user’s micro-environment.
This means UV data is taken from the wearer’s surroundings, tracking exposure whether they’re in direct sunlight or sitting inside near a window.
The companion app then combines this data with a personalized skin profile, tracking the user’s specific skin type, protective clothing, and morning sunscreen application.
The goal, the brand says, is to provide the missing environmental data required to turn sunscreen from a static ritual into an adaptive, responsive routine based on real exposure.
The Wareable take: One to track
The pedigree behind the company makes this a launch worth watching. The90 was founded by CEO Stacy Salvi, a veteran health-tech executive who spent over a decade guiding major hardware for both Fitbit (and then, following its $2.1 billion acquisition, Google).
Wearables that can leverage localized environmental factors are a rapidly growing area of the market.
There were a couple of similar offerings to the Gem in the 2010s from the likes of L’Oréal/La Roche-Posay and Gatorade, the latter of which has seen notable success since partnering with Epicore Biosystems.
However, this specific type of live tracking via patches and pendants has exploded over the last 2-3 years. We tracked one of the early consumer-facing sweat trackers during the 2024 London Marathon as a field test, but brands are now delivering different concepts via their own localized trackers each and every quarter.
At $299, this is still an expensive and niche proposition. However, in the age of red light therapy and advanced sleep trackers, there’s no reason why sun exposure can’t also become a notable measurable health metric.
And if it does begin trending, The90 could find itself at the forefront of a lucrative and important corner of the premium wellness market, thanks to its early entry.
