The90 Gem: Smart Jewelry Pendant for Real-Time UV Tracking

The90 Gem is a modular UV-tracking pendant that monitors UVA and UVB exposure in real time to prevent premature skin aging. According to The90, the wearable syncs with a mobile app to provide personalized sunscreen reminders and exposure thresholds based on a user’s specific skin profile and daily habits.

Why does real-time UV tracking matter for skin health?

Cumulative, everyday sun exposure causes up to 90% of visible skin aging and premature damage, according to The90. Most people associate skin damage with long beach days, but the company notes that UVA rays penetrate windows, making indoor or urban environments a source of constant exposure.

The distinction between ray types is critical for prevention. The90 identifies UVA rays as the primary driver of long-term aging, while UVB rays are more closely linked to immediate sunburns. By tracking both, the Gem provides a more complete picture of skin stress than a standard weather app forecast.

Did you know? UVA rays don’t just hit you outdoors. Because they can pass through glass, you can accumulate skin-aging damage while sitting in a car or near a window at home.

How does the The90 Gem differ from traditional smart wearables?

While most wearable tech companies are currently racing to integrate general-purpose AI into every feature, The90 has designed the Gem for a single, specific utility. Instead of managing notifications or counting steps, the device serves as a dedicated sensor for solar radiation.

The hardware is built as modular smart jewelry, available in gold and silver. This allows it to function as a standard pendant rather than a piece of plastic tech. The company claims the device offers seven days of battery life with a two-hour charging cycle.

From a functional standpoint, the Gem moves beyond generic UV indices. It feeds live data into an app where users create a personal skin profile. This profile incorporates skin type and existing sun-protective habits to calculate tailored guidance, rather than applying a one-size-fits-all warning to every user.

Pro Tip: Don’t rely on the “cloudy day” myth. UV rays penetrate cloud cover, which is why real-time sensors are more reliable than visual cues for knowing when to reapply sunscreen.

What happens next for personalized sun protection?

The shift toward “precision skincare” is moving away from static SPF ratings toward dynamic, data-driven application. The90 Gem implements this by offering personalized UV thresholds and sunscreen reapplication reminders based on actual exposure levels rather than a timer.

This approach addresses a common failure in sun protection: the gap between when sunscreen is applied and when it actually expires under specific intensity levels. By monitoring the actual rays hitting the skin, the technology allows users to time their protection based on real-world conditions.

The device is splash-resistant, though The90 advises against full submersion. This limitation suggests a future trend where specialized sensors may eventually be integrated into waterproof materials for athletes and swimmers who face the highest risks of UV damage.

Frequently Asked Questions

How much does the The90 Gem cost?
The device is priced at $299, though the company has offered an early access price of $199 through its website.

Can I wear the Gem in the shower?
The90 states the device is splash-resistant, but it warns users not to fully submerge the necklace in water.

What is the difference between UVA and UVB tracking?
According to The90, UVA rays are associated with long-term skin aging and can pass through windows, while UVB rays are the primary cause of sunburns.

How long does the battery last?
The company claims the battery lasts up to seven days on a single charge, which takes approximately two hours.

Do you track your daily UV exposure, or do you rely on the weather forecast? Let us know your skincare routine in the comments below or subscribe to our newsletter for more updates on health tech.