Gemetrix vs Diamond Tester
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Gemetrix
Control your smartphone camera's exposure, ISO, color temperature, and focus for both short-wave and long-wave UV illuminations. Compare captured images side-by-side or with a slider, and save them with clear labeling.
- UV illumination control (SWUV & LWUV)
- Adjustable exposure, ISO, color temperature, focus
- Side-by-side image comparison
- Image slider comparison
- Save labeled images
Read full descriptionHide full description
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.
Diamond Tester
Identify real diamonds, gems, and crystals with a photo. Get information on authenticity and estimated value. Organize your findings in a personal collection.
- Photo-based diamond identification
- Authenticity verification
- Estimated diamond value
- Gem and crystal analysis
- Personal collection organizer
Read full descriptionHide full description
Diamond Tester helps you explore and learn about diamonds, gems, and crystals through visual reference. Take a photo of any stone in your collection to receive educational information about its visual characteristics and properties. KEY FEATURES - Visual identification reference for gemstones and crystals - Educational information about the 4 C's (Cut, Clarity, Color, Carat) - Value range estimates based on visible characteristics - Personal collection management to organize your scans - Learn section with gemology basics and stone properties HOW TO USE For best results, place your stone in a clean, well-lit area and take a clear photo. The app will provide visual reference information and educational content related to the characteristics it identifies. PERFECT FOR - Jewelry enthusiasts learning about gemstones - Collectors organizing their stone collections - Students studying gemology basics - Anyone curious about the gems they own - Quick reference for visual stone characteristics YOUR COLLECTION Build and organize your personal gemstone library. Save scans, add notes, and track your collection over time. All data stays on your device. IMPORTANT INFORMATION This app is an educational reference tool. The information provided is for general learning purposes and visual identification reference only. It is NOT a substitute for professional gemological testing or appraisal. For authentication, valuation, or any decisions involving significant financial value, always consult a certified gemologist (GIA, AGS, or equivalent) who can perform proper testing with calibrated equipment. The app cannot definitively verify the authenticity, grade, or precise value of diamonds, gemstones, or crystals. Visual identification has inherent limitations and should be used as a starting point for learning, not as final verification. ____________ Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://meliann.notion.site/Privacy-Policy-For-Diamond-Tester-2a3476f8f041805cb09cea52c0f092d1?pvs=73
Screenshots
Verdict
The clearest difference is review sentiment: Gemetrix at 50% against Diamond Tester's 0%. Gemetrix also leads on in-app purchases (none vs 2) and iOS requirement (10.3 vs 17.6). Diamond Tester's advantage is rating (4.5 vs 2.2) and ratings volume (65 vs 5). On price, update cadence, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Diamond Tester sells 2 in-app purchases, starting at $7.99 per 7 days. Gemetrix asks for nothing beyond the download.
Diamond Tester holds the better App Store score, 4.5 against 2.2. That said, the two scores are not equally well evidenced: Diamond Tester has 65 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 50% of Gemetrix's written reviews are positive against 0% of Diamond Tester's, so the app with the better star average is not the one people write more warmly about.
Gemetrix ships an update monthly, Diamond Tester fortnightly. The most recent releases landed on November 2, 2026 and October 31, 2026 respectively.
| Parameter | Gemetrix | Diamond Tester |
|---|---|---|
| Price | Free | Free |
| Rating | 2.2 (5 ratings) | 4.5 (65 ratings) — better |
| Positive reviews | 50.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 5 | 65 — better |
| Update frequency | Monthly | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 10.3 — better | 17.6 |
| Further details — not scored | ||
| Size | 18 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | John Chapman | Nicolas Gustavo Melian |
Customer experience
Gemetrix
Diamond Tester
In-app purchases
Gemetrix
No in-app purchases
Diamond Tester
- Weekly Plan3 Days trial$7.997 Days
- Yearly Plan$24.991 Year
Questions
Is Gemetrix free?
Is Diamond Tester free?
Which has better reviews, Gemetrix or Diamond Tester?
Do Gemetrix or Diamond Tester have ads?
Which is updated more often, Gemetrix or Diamond Tester?
Other comparisons















