The90 Gem smart necklace monitors the sun before you get burned. It's backed by a former Fitbit executive.

Smart rings and watches today can count every heartbeat, step, and hour of sleep, but the sun – which dermatologists say is responsible for most skin aging – hasn’t been properly monitored by any wearable device yet. The90 startup, founded by a former Fitbit executive, aims to fill this gap with a piece of jewelry that detects impending sunburn before you do.

What the The90 Gem necklace can do

The Gem looks like an ordinary pendant on a chain and is said to be indistinguishable from regular costume jewelry during the day. Inside, however, are sensors that continuously monitor two components of ultraviolet radiation – UVA, which causes skin aging, and UVB, which causes sunburn. Unlike a classic UV index, which is based only on location and weather, the pendant reads the dose you are actually receiving – even if you are sitting by a window or behind car glass.

The measured data is sent to an app for both iPhone and Android. This app first creates your skin profile based on skin type, habits, and sun sensitivity and calculates personal limits from it. In practice, this means your phone will estimate how long it will take you to get burned at the current radiation level and will let you know when to apply sunscreen, put on clothes, or seek shade.

Where did the name The90 come from?

The name refers to a statistic that the manufacturer likes to repeat: up to 90 percent of visible skin aging – wrinkles, fine lines, and pigment spots – is reportedly not due to age, but to the sun. Hence the entire idea behind the device: to measure exposure before it has a chance to leave its mark on your face.

The project is led by CEO Stacy Salvi, who has spent over ten years in the world of wearable electronics. Among other things, she led the business negotiations that resulted in Google’s acquisition of Fitbit for 2.1 billion dollars, is the daughter of a dermatologist, and previously participated in the development of a smart ring for women. Lauryn Bosstick from the popular podcast The Skinny Confidential is also among the company’s investors.

Price and availability

The90 Gem is sold directly through the manufacturer’s website, currently at an introductory price of 199 dollars instead of the later/standard 299 dollars (approximately 4,200 and 6,200 Czech crowns, respectively). The company promises free shipping, a one-year warranty, and a thirty-day return period; orders placed now are expected to ship in June.

Would you wear a piece of jewelry that monitors how much sun exposure you get in a day?

Sources: Engadget, The90, PR Newswire