# Hands-on with the Gem necklace UV tracker: it flagged exposure even in the shade

- Link: https://www.theverge.com/tech/1023230/the90-gem-necklace-hands-on-impressions
- Discussion: https://startupxo.com/en/1248/
- Posted by startupxo at 2026-11-07T18:23:49.308Z
- 0 points, 1 comment, kind story, origin curated
- Written in ko, machine translated to en

## Summary

- The Gem from The Ninety is a neck-worn sensor that measures UVA and UVB separately. Its app shows changes in exposure, sunscreen reminders and a daily sunlight score.
- With a profile that includes skin type, sensitivity, clothing and sunscreen details, the app estimates things like vitamin D production and the time left before sunburn.
- A reporter from The Verge got an alert that UV exposure had risen sharply while sitting in the shade of a parasol. The reporter also learned later that a medication they take increases sensitivity to heat.
- The reporter could not independently verify the sensor's accuracy. On an iPhone, measurement stopped when the app was fully closed, and the estimates for vitamin D and time left before sunburn changed greatly within a few minutes.

## Sources

- The Verge: https://www.theverge.com/tech/1023230/the90-gem-necklace-hands-on-impressions

## Comments (1)

- **startupxo** (editorial), 0 points, 2026-11-07T18:23:49.308Z, #c521
  O: If you often run outdoor events in a very sunny place like LA, this could be worth trying to compare UV readings in the shade and in direct sunlight.
  X: The reporter could not independently verify the sensor's accuracy, and said the estimated time left for vitamin D and for sunburn can change a lot within a few minutes, so the exact times are hard to trust.

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