Your phone cannot see your skin. The Gem can.
For generations, the relationship between human skin and sunlight has been managed by intuition and approximation — a morning ritual of sunscreen, a glance at a weather app, a hope that the protection holds. In June 2026, a health-tech company founded by a former Fitbit-era Google executive introduced The90™ Gem, a $299 smart jewelry pendant that replaces regional UV estimates with real-time, skin-level optical sensing. The device arrives at a quiet but consequential frontier: the recognition that up to 90 percent of visible skin aging is not the work of time, but of light we never thought to measure.
- Decades of sun protection advice have rested on a flawed assumption — that a zip-code UV estimate on a smartphone tells you anything meaningful about the light actually reaching your skin.
- Cumulative, unmeasured UV exposure silently drives the wrinkles, hyperpigmentation, and cellular degradation that billions of dollars in skincare products are designed to reverse after the fact.
- The90™ Gem embeds optical sensors directly into wearable jewelry, tracking both UVA and UVB rays in real time and feeding encrypted data to a companion app that builds a personalized skin profile.
- Rather than a generic timer, the app calculates SPF degradation curves and sends haptic alerts precisely when an individual's applied sunscreen has lost enough efficacy to require reapplication.
- Backed by wellness entrepreneurs and priced as a premium preventative tool, the Gem is now navigating the critical question of whether consumers will trust a piece of jewelry to reveal what their eyes — and their phones — have never been able to see.
Stacy Salvi, a health-tech executive who helped shape the Fitbit era at Google and later designed smart rings for women, has built her next company around a disarmingly direct observation: most people are protecting their skin blind.
The product is The90™ Gem, a $299 smart jewelry pendant with built-in optical sensors that measure actual ultraviolet radiation hitting the skin in real time. The gap it addresses is larger than it first appears. The UV Index on a smartphone is a regional estimate — calculated by zip code, indifferent to whether you are sitting in a shaded room, driving through glass, or walking a sun-drenched street. The Gem sees what the phone cannot.
The company emerged from stealth in June 2026 with backing from Lauryn Bosstick of The Skinny Confidential and founders from Life360, Blenders Eyewear, and Cuts Clothing. Its founding insight is dermatological: up to 90 percent of visible skin aging — wrinkles, loss of elasticity, hyperpigmentation — comes not from time itself but from cumulative UV exposure absorbed in small, untracked moments. Most people apply sunscreen once in the morning. The sun does not operate on that schedule.
The Gem tracks both UVA rays, which penetrate glass and drive deep cellular aging, and UVB rays, which cause surface sunburn. That data streams to a companion app that builds a personalized profile based on Fitzpatrick skin type and sensitivity. The app then calculates SPF degradation in real time and sends haptic and push alerts when reapplication is actually warranted — not on a generic timer, but at the individual's true UV threshold. It also identifies windows of safe sun exposure that support systemic health without accumulating damage.
At $299, the Gem is positioned as a premium preventative device rather than a mass-market gadget — jewelry first, sensor second. The deeper innovation is the data loop itself: turning invisible light into continuous, hyper-localized intelligence. For consumers already spending heavily on clinical treatments and specialized sunscreens, it offers something the market has not previously provided — auditable, real-time feedback on the primary driver of the aging they are working so hard to prevent.
Stacy Salvi, the health-tech executive who spent over a decade at Google during its $2.1 billion acquisition of Fitbit and later designed award-winning smart rings for women, has launched a new company with a deceptively simple premise: most of us are protecting our skin blind.
The product is The90™ Gem, a $299 smart jewelry pendant embedded with optical sensors that measure the actual ultraviolet radiation hitting your skin in real time. It sounds like a small thing—a piece of jewelry that knows about light. But the gap it fills is substantial. For decades, people have relied on the UV Index displayed on their phones, a regional estimate calculated by zip code that tells you nothing about whether you're sitting in a shaded office, driving behind a car windshield, or walking down a reflective city street. Your phone cannot see your skin. The Gem can.
The company emerged from stealth in June 2026 with backing from Lauryn Bosstick, founder of The Skinny Confidential, and entrepreneurs from Life360, Blenders Eyewear, and Cuts Clothing. The founding insight is rooted in dermatological fact: up to 90 percent of visible skin aging—wrinkles, fine lines, loss of elasticity, hyperpigmentation—comes not from the passage of time itself but from cumulative, unmeasured ultraviolet exposure accumulated in small moments throughout the day. Most people apply sunscreen once in the morning and then forget about it. The sun does not forget.
The distinction between UVA and UVB rays matters here. UVA rays are present from sunrise to sunset and penetrate through window glass; they drive deep cellular degradation and long-term aging. UVB rays are shorter-wavelength and cause the surface inflammation we recognize as sunburn. The Gem's sensors track both, streaming encrypted data to a companion app that builds a personalized profile based on your Fitzpatrick skin type and sun sensitivity. The app then does something conventional sunscreen routines cannot: it tells you, in real time, when your applied SPF has degraded enough to warrant reapplication. It sends haptic and push notifications triggered by your actual UV threshold, not a generic timer. It maps out safe windows for natural light exposure—the kind that supports systemic health—while protecting against cellular damage.
The market for this exists at the intersection of two truths. Women spend billions annually on clinical treatments, antioxidant routines, medical-grade topicals, and specialized sunscreens designed to protect skin longevity. Yet the baseline method for tracking the primary threat to that longevity has not evolved. The smartphone weather app remains the standard. Bosstick, in her role as company advisor, framed the problem plainly: most people are still guessing about sun exposure, applying products without knowing whether those products are still working, missing the small moments of exposure that accumulate into visible damage.
At $299, the Gem positions itself as a premium preventative tool rather than a mass-market device. It is jewelry first—designed to be worn—and a sensor second. The real innovation is not the hardware but the data loop: transforming invisible light into hyper-localized, actionable intelligence. For a consumer already invested in skin health, the Gem offers something that has been missing from the market: auditable, continuous feedback on the primary driver of aging. It moves sun protection from a static morning ritual into a dynamic, personalized system. Whether that shift proves meaningful will depend on whether people are willing to let a piece of jewelry tell them what they have been unable to see on their own.
Citas Notables
Women are already investing in SPF, treatments, tools, and routines to protect their skin, but when it comes to sun exposure, most of us are still guessing. The UV Index on your phone doesn't know your skin, your sunscreen, or the small moments of exposure that happen throughout the day.— Lauryn Bosstick, founder of The Skinny Confidential and company advisor
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Why does this matter more than just reminding people to reapply sunscreen every two hours?
Because two hours is a guess. Your sunscreen degrades differently depending on whether you're sweating, swimming, or sitting under an umbrella. The Gem measures your actual UV load and tells you when your specific protection has worn down. It's the difference between a schedule and reality.
But people have known for years that sun damage accumulates. Why hasn't this existed before?
The sensors didn't exist at a price point that made sense for a consumer product. And honestly, the framing was wrong. This isn't about scaring people into more sunscreen. It's about giving them data so they can make decisions—including when it's actually safe to be in the sun without reapplying.
Who is the actual customer here? Is this for dermatologists or for regular people?
Regular people who are already spending money on skin care. The person who buys a $200 serum isn't going to balk at $299 for a tool that tells them whether that serum is actually being protected. It's for people who take skin health seriously but feel like they're working in the dark.
The source mentions UVA penetrates through window glass. Does that mean you need to wear this indoors?
That's the insight, yes. Most people think they're protected when they're inside. But UVA comes through windows. So if you're working at a desk near a window all day, you're accumulating exposure you can't see. The Gem would catch that.
What happens to the data? Does the company keep it?
The source says the data streams via encrypted wireless protocols and the app cross-references it with your skin profile. It doesn't specify what happens after that, but for a health device, that's the question people should be asking.
Is this actually preventative or is it just better tracking?
It's both. Better tracking lets you prevent damage you would otherwise accumulate. But the real prevention is the reapplication prompts—you're actually changing behavior based on real data instead of guessing. That's where the aging prevention happens.