Comparison

Gemetrix vs Diamond Tester

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

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

About

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.

Highlights
  • Photo-based diamond identification
  • Authenticity verification
  • Estimated diamond value
  • Gem and crystal analysis
  • Personal collection organizer
Features
Read 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

Gemetrix4 screens
Diamond Tester4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

Gemetrix ships an update monthly, Diamond Tester fortnightly. The most recent releases landed on November 2, 2026 and October 31, 2026 respectively.

Scorecard6 real differences · 4 level
Gemetrix versus Diamond Tester: the parameters behind the verdict, then further details
ParameterGemetrixDiamond Tester
PriceFreeFree
Rating2.2 (5 ratings)4.5 (65 ratings) — better
Positive reviews50.0% of reviews — better0.0% of reviews
Number of ratings565 — better
Update frequencyMonthlyFortnightly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad
Requires iOS10.3 — better17.6
Further details — not scored
Size18 MB12 MB
Age rating4+4+
DeveloperJohn ChapmanNicolas Gustavo Melian

Customer experience

Gemetrix

All ratings5 ratings
Positive20.0%
Neutral20.0%
Negative60.0%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

Diamond Tester

All ratings64 ratings
Positive85.9%
Neutral1.6%
Negative12.5%
Written reviews3 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Gemetrix

No in-app purchases

2 purchases

Diamond Tester

Subscriptions2
  • Weekly Plan3 Days trial$7.997 Days
  • Yearly Plan$24.991 Year

Questions

Is Gemetrix free?
Gemetrix is free to download, with no in-app purchases.
Is Diamond Tester free?
Diamond Tester is free to download, with in-app purchases available.
Which has better reviews, Gemetrix or Diamond Tester?
Diamond Tester is rated higher. Gemetrix averages 2.2 out of 5 from 5 ratings, while Diamond Tester averages 4.5 from 65 ratings.
Do Gemetrix or Diamond Tester have ads?
Neither Gemetrix nor Diamond Tester shows ads.
Which is updated more often, Gemetrix or Diamond Tester?
Gemetrix ships an update monthly, and Diamond Tester fortnightly. Most recently, Gemetrix was updated on November 2, 2026 and Diamond Tester on October 31, 2026.

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