# Gemetrix — Capture diamond fluorescence

> Smartphone camera control for UV fluorescence imaging and comparison. (iPhone/iPad app by John Chapman.)

- Source: https://appshunter.io/ios/app/gemetrix/id1363103077 (this page in markdown: same URL + `.md`)
- Developer: [John Chapman](https://appshunter.io/developer/1363103076)
- Category: Utilities, Photo & Video
- Price: Free
- Rating: 2.20/5 from 5 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 10.3 · 18 MB
- Languages: American English
- Released: 2018-03-27
- Data updated: 2026-06-01
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/gemetrix/id1363103077/reviews.md

## What is Gemetrix?

This app allows control of your smartphone camera, using the same settings for both short-wave ultra-violet (SWUV) and long-wave ultra-violet (LWUV) illuminations.  The controlled settings are for exposure, ISO, color​ temperature and focus.  The two images can then be compared either through alternating views or using a slider.  Images with SW and LW labeling can be saved to your image gallery.

## Key features

- UV illumination control (SWUV & LWUV)
- Adjustable exposure, ISO, color temperature, focus
- Side-by-side image comparison
- Image slider comparison
- Save labeled images

## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/gemetrix/id1363103077/reviews.md

### 1/5 — Useless

*2023-06-03*

Would give 0 stars if possible.

### 5/5 — Perfect!

*2018-03-29*

Just what I need, works perfectly!

## Frequently asked questions about Gemetrix

### What is Gemetrix used for?

Gemetrix allows you to control your smartphone camera's settings like exposure, ISO, color temperature, and focus specifically for capturing images under short-wave and long-wave ultraviolet (UV) light. This is particularly useful for observing and comparing diamond fluorescence.

### Does Gemetrix have ads?

No, Gemetrix does not contain advertisements. It is a free application that focuses on providing camera control features without interruptions.

### What devices does Gemetrix support?

Gemetrix is designed to work on iPhones and iPods. It allows users to leverage their device's camera for specialized UV imaging.

### How can I compare images in Gemetrix?

Gemetrix offers two methods for comparing images captured under different UV illuminations: an alternating view mode and a slider tool. This helps in analyzing subtle differences in fluorescence.

### Is Gemetrix suitable for beginners?

Gemetrix is rated for ages 4 and up, indicating a general accessibility. However, its specific use case for UV fluorescence analysis might appeal more to users with a particular interest in gemology or specialized photography.

### When was Gemetrix last updated?

The latest version of Gemetrix, 1.1.1, was released on October 17, 2018. The app was initially released on March 27, 2018.

### What is the user rating for Gemetrix?

Gemetrix has an average rating of 2.2 stars based on 5 user reviews. This suggests that while the app offers specific functionality, user satisfaction may vary.

## Version history (last 5 releases)

### 1.1.1 — 2018-10-17

Minor bug fixes.

### 1.1.0 — 2018-09-08

Support for Melee and PL images to be taken and stored. Images are now all stored in a Gemetrix album in your photo library for easy access.Minor bug fixes.

### 1.0.2 — 2018-04-12

- save a photo to the album in the gallery 
- you can choose photos from gallery 
- improve stability​

### 1.0.1 — 2018-03-31

- fix crash on the second startup
- update preview

### 1.0 — 2018-03-27

No release notes.

## Apps similar to Gemetrix

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [SmartPro Instrument](https://appshunter.io/ios/app/smartpro-instrument/id1341580615) | 1.8 (8) | Free | Utilities |
| [Gemstone Identifier: Diamond](https://appshunter.io/ios/app/gemstone-identifier-diamond/id6742844565) | 4.0 (4) | Free | Utilities |
| [Rollei SafetyCam](https://appshunter.io/ios/app/rollei-safetycam/id910464400) | — | Free | Utilities |
| [Sherlock Holmes Detect](https://appshunter.io/ios/app/sherlock-holmes-detect/id1617998548) | 4.2 (6) | Free | Utilities |
| [Rock Identifier by Picture ID](https://appshunter.io/ios/app/rock-identifier-by-picture-id/id1582182059) | 3.1 (138) | Free | Utilities |
| [Jewelers' Assist](https://appshunter.io/ios/app/jewelers-assist/id1367390992) | 4.7 (136) | Free | Utilities |

## More apps by John Chapman

- [GemlogisUSA Inspector](https://appshunter.io/ios/app/gemlogisusa-inspector/id6446342793)

All apps by John Chapman: https://appshunter.io/developer/1363103076

## Related topics

[gemetrix](https://appshunter.io/ios/topics/gemetrix)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*