The90 Gem
Get the good out of the sun. Own your light.
The90 Gem is a precision UVA and UVB sensor disguised as fine jewelry. It reads the light your skin actually gets, the vitamin D and morning light you want and the aging and burning you don't, and turns all of it into your Sun Score: one daily number from 0 to 100. Collect the good, stay under your limits, and aim for The90.
Gold or silver, made to wear every day, with the free app included and no subscription.
Orders placed today will ship in 1-2 business days
App Features
✓ Your daily Sun Score, one number from 0 to 100 that rewards balance. Aim for The90.
✓ Reads the UVA (aging) and UVB (burning) actually reaching your skin in real time, not a regional forecast.
✓ Tracks the good too: estimated vitamin D and the morning light that supports your energy, mood, and sleep.
✓ Personalized to your skin profile, so the guidance is yours, not a generic recommendation.
✓ Nudges you when it's time to reapply, cover up, or step out for morning light.
✓Daily journal and full history turn your Score into a trend you can watch over time.
Product Specs
✓ Premium gold and silver finishes on the gem, pendant, and chain
✓ 7-day battery life allows for continuous monitoring
✓ Quickly charges in just 2 hours
✓ Splash-Proof, do not submerge
✓ Product size similar to the diameter of a US nickel
30-day return policy
1-year warranty
Free shipping
No Subscription
The90 Gem
specs and details
Tech specs
Everything The Gem measures, and what it is made of.
Sensors and measurement
UV sensor: A UV photodiode that reads both UVA (the aging rays) and UVB (the burning rays) separately, so you get a fuller picture than the single UV Index number on your weather app.
Motion sensor: A 3-axis accelerometer that knows when you are actually wearing The Gem, so your Sun Score reflects your real day. It only ever senses movement and UV. It does not track location or anything else.
What it measures: Real-time UV intensity plus your cumulative dose over the day, reported in the internationally recognized UV Index (UVI), with UVA and UVB captured individually.
Design and materials
Finish: Titanium PVD coating in premium gold or silver, across the Gem, pendant, and chain, chosen for durability as much as shine.
Size: About the diameter of a US nickel. Small enough to layer with the jewelry you already wear.
Modular design: The Gem is a removable core. It lifts out of the pendant so it can move into new form factors as they launch, including an upcoming clip. You buy the sensor once.
Water resistance: Water resistant up to 1 meter for 30 minutes. Rain, sweat, and a rinse are fine. Skip the pool, the shower, hot tubs, and saunas.
Battery and connectivity
Battery life: 7 or more days of everyday wear on a single charge, so topping up is a weekly habit, not a nightly one.
Charging: About 2 hours to full, using the included proprietary magnetic charger. A color LED tells you at a glance when it is pairing and charging.
Connectivity: Bluetooth Low Energy, which syncs your readings to the app while sipping battery.
What’s in the box
Everything you need to start reading your light, right out of the box.
● The Gem, your removable UV sensor, in the finish you chose.
● The pendant, with The Gem set inside and ready to wear.
● A matching chain in the same gold or silver finish.
● The magnetic charging cable, made specifically for The Gem.
● A quick-start card to get you set up and syncing in a few minutes.
Then download the free The90 app, build your skin profile, and you are ready. No subscription, no add-ons to buy
Shipping & returns
Free shipping, a 30-day window to change your mind, and real people if you need us.
Shipping
Free standard shipping on every order, dispatched from California within 1 to 2 business days. You will get a tracking email the moment your Gem is on its way. Need it sooner? Expedited and overnight options are available at checkout.
We currently ship within the United States only.
Returns
Try The Gem for 30 days. If it is not for you, send it back for a full refund. We cover return shipping within the US and refund your original payment within 5 business days of your Gem arriving back with us.
Everyday wear from actually using it is expected and completely fine. We would rather you tested it through real days in real sun than left it in the box
Warranty
Every Gem is covered for one year. If something goes wrong through normal use, we will make it right.
What's covered
Your one-year limited warranty covers manufacturing defects. If the sensor stops reading correctly, the battery fails to hold a charge, the charger stops working, or the finish or housing fails under normal wear, we will repair or replace it at no cost to you.
What's not covered
● Loss or theft.
● Accidental or drop damage beyond reasonable everyday wear.
● Water damage beyond the rated water resistance, including the pool, shower, hot tubs, and saunas.
● Damage from unauthorized repairs or modifications.
How to make a claim
Reach out at support@the90.com with your order number and a short description of what is happening. A real person will take it from there, and if a return is needed we will send a prepaid label.
Try it through a season of sun.
30-day returns
Don't love it, send it back.
1-year warranty
Covered against defects.
Free shipping
On every order.
No subscription
The app is included.
I think this device/jewelry is genius. It’s beautiful, it’s purposeful, and for someone who genuinely takes exceptional care of my skin, I really appreciate how user friendly it is. It’s also very eye opening to see how much sun exposure I’m getting.
As feedback for future updates, I would love to see an option to put in a sunscreen application after the fact (like if I wanted to put it in the app 30 min or an hour after I applied, it would be nice to be able to adjust the time of application).
As soon as I saw this device i knew I had to have it. The gem looks amazing with my necklace stack and having the UV exposure data is so important to me that I check the app everyday! Thank you for such a genius product.
I truly can’t say enough positive things about this device. As a stage III melanoma patient, I never fully understood the impact of UVA and UVB exposure before my diagnosis. Having a sensor that shows me exactly how much UV exposure I’m experiencing has been genuinely life-changing. And, for someone in my position… truly life-saving.
The app is fantastic, intuitive, and incredibly easy to use. The necklace itself is also stylish, comfortable, and easy to wear every day. It blends seamlessly into my outfits, which makes staying protected feel effortless. I’m so grateful for the peace of mind this device gives me.
I rave about this necklace to all of my fellow Southern Californian friends (where the UV index is currently at 11) and my oncology team.
Stephanie, we are so happy to hear the value you are getting out of The90 Gem. We wish you the best of luck for you on your journey and are here to support you.
I’ve been wearing The90 Gem daily and really enjoy it. It’s sleek, comfortable, and genuinely looks like jewelry while making my daily UV exposure much easier to understand. I especially like the UV alerts and personalized exposure data. I can't wait to see what more is coming to the app, as I know they are working on updates!
*Gifted product; all opinions are my own.*
I purchased this for my mom and she absolutely loves it. My parents live on a lake a spend a lot of time outdoors. She was telling me she is way more aware of how much sun she is getting now and looking for ways she can stay more protected. She was saying she wishes she could see past days exposure.
I love it! And once this app has some of the upgrade features they said are coming this is going to be such an amazing everyday piece of jewelry. It looks so cool layered with all of my other necklaces.
We are working hard to make your experience better and better.
My husband got me one when Lauryn posted it. Love it!
Isn't Lauryn the best?!?
Ordered this for my wife and so far she loves it. She works in an office and long hours. She was having some health issues and I told her it's possibly a lack of movement throughout the day and/or the lack of sunlight she was getting. This has been a nice reminder for her to get outside a few times a day and get sun. We will see if it improves her health.
Happy to hear your wife is loving The Gem. Getting the proper amount of sunlight is so important.
I'm an esthetician and obsessed with skin protection. Everything from hats to driving gloves to multiple types of sunscreen. I FINALLY have a tool to give me data around my routines.
Having your support means the world to us!
The device had some issues connecting to my Android phone, and it took a few tries and resets to finally get it connected. Seems to work fine now, and the UV measuring seems to be accurate. Doesn't stay connected to the phone constantly, so some notifications are delayed until it syncs.
Would you mind shooting us an email at support@the90.com so we can learn more about your phone and the issues you are experiencing. Thank you for your support.
So far the app seems very trustworthy and I love the black onyx look
Happy to hear The Gem is fitting with your style!
Big fan so far. I've worn it and checked the app everyday.
Love this!
Once you start wearing this (pretty) necklace and geeking out on the data, you never want to take it off. I love the reminders and find the content and sun exposure updates so helpful. We really do not realize how much sun we are getting day to day!
Love that you are getting so much value out of wearing The Gem. Let us know if you have any questions or feedback along the way.
My wife is extremely fair skinned and is always diligent about sun exposure. So…needless to say she LOVES The90 Gem! She can’t wait to see what additional features you add to the app. The one thing she would love to see is the ability to order more charging cables. (We are on a 2 month trip and she forgot to pack the charger, but she is enjoying the product while she can.
Thanks for sharing this with us. We are excited to be part of your wife's journey and will continue to develop more features for her.
We also hear you on the charger and are working on it.
Great novelty. Easy to order and fast delivery.
Very helpful staff. Very fast response on few questions related to the use of the item.
Keep up your great work.
Love to hear that. Thank you.
Never stays connected to my phone. Ive reached out to customer service 3 times and no response. When it does connect, the readings on the all are the same every time. I am disappointed in this and was really excited to get this. Hasn't been a good experience at all and expensive for it to not work
So sorry to hear you are experiencing issues with connectivity. We aren't seeing your customer service inquiry, but have reached out directly.
The pendant is a bit flimsy.
And the app definitely needs a lot of work that I still feel like I am getting some value out of this
Thank you so much for your feedback. We are working to continually improve the app experience for users. Anything specific you would like to see?
The gem works great i am just confused on how to ciramin d tracking works. I am currently comparing it to my stand alone manual uv index app and after 30 minutes in the sun i only had 14% vitamin d yesterday while the manual app has it over 100% do to high uv index even with sunscreen.
This is the problem with UVI vs tracking UVB specifically. UVI is a regional weather report that doesn't account for the actual exposure you are getting. It also doesn't factor in your genetics, clothing, or sunscreen application like The90 Gem. Our algorithms are built by leading dermatologists and photobioloists.
FAQs
Do I have to wear it on a necklace?
Only if you want to. The Gem is the sensor, and the way you wear it is up to you. It clips into the pendant and necklace that come in the box today, and it is built to move into new mounts as they launch, including a hat clip and a bag tag. You buy the sensor once and wear it the way your day actually looks.
When will the hat clip / bag tag ship?
Both are in development. We will announce dates once we are confident we can hit them, and email subscribers hear first. The part that matters now: the Gem you buy today is the same sensor that clips into everything we release later, so nothing you own becomes obsolete.
Can I wear it in the shower or pool?
The Gem is splash-proof, so sweat, rain, and a rinse at the sink are all fine. It is not built for submersion, so take it off before you swim, shower, or get in a hot tub. We recommend while swimming that you place The Gem in the same direct sunlight you are receiving.
How accurate is it?
The Gem reads UVA and UVB separately, in real time, from wherever it sits on your body. That is a different kind of accuracy than a forecast: rather than estimating conditions across your region, it measures the light actually reaching you. How those readings become guidance was developed with Dr. Richard Weller, a UV specialist who
has spent his career studying how light affects skin.
Is it FSA/HSA eligible?
The90 Gem is not currently FSA/HSA eligible.