# Lithify: Geology Field Guide — Rock & Mineral Field Guide

> Rock & Mineral Field Guide (iPhone/iPad app by Robert Corbin.)

- Source: https://appshunter.io/ios/app/lithify-geology-field-guide/id6792598886 (this page in markdown: same URL + `.md`)
- Developer: [Robert Corbin](https://appshunter.io/developer/1890247992)
- Category: Reference, Education
- Price: $2.99
- Age rating: 4+
- Requires: iOS 17.0 · 115 MB
- Languages: American English
- Released: 2026-07-29
- Data updated: 2026-08-11
- User reviews in markdown: https://appshunter.io/ios/app/lithify-geology-field-guide/id6792598886/reviews.md

## What is Lithify?

Lithify is a serious, offline field guide for rockhounds, geology students, prospectors and hikers. It pairs a genuine identification engine with a richly illustrated reference library of 101 rocks and minerals — all on your device, with no account, no subscription, and no photos leaving your phone.

Most rock-ID apps upload your pictures to a cloud service and hide the answer behind a subscription. Lithify takes the opposite approach: it teaches you to identify a specimen the way a geologist does — by its diagnostic properties — and shows its work every step of the way.

IDENTIFY, HONESTLY
• Dichotomous Key — an adaptive question-and-answer key that starts from luster, hardness and streak and narrows the field with each answer, showing the live candidate count so you always know where you stand.
• Property Matcher — enter whatever you observed (hardness band, streak color, cleavage, magnetism, acid reaction, color) and get a ranked shortlist scored by how well each specimen agrees. Partial information still helps.
• Photo Color Assist — sample a photo's dominant colors on-device to suggest color-consistent candidates. It is an aid, never an automatic verdict — and it is honest about that.

A REAL REFERENCE LIBRARY
• 69 minerals and 32 rocks (igneous, sedimentary, metamorphic), each with a curated photo gallery.
• Factual structured properties: Mohs hardness, streak, luster, cleavage, fracture, specific gravity, crystal system, chemical formula, diaphaneity, tenacity, magnetism and acid reaction.
• Classification by mineral group plus Dana and Strunz numbers.
• Formation environments, notable localities, common uses, and field-identification tips for every entry.
• Search and filter by type, rock class, hardness band, and color.

FIELD TOOLS
• Mohs Scale — the ten index minerals, common field-test tools (fingernail, copper coin, steel, glass), and how to run a proper scratch test.
• Specific Gravity Calculator — compute SG by the hydrostatic (Archimedes) method or mass ÷ volume, then match your result against minerals of that density. Real physics, not a lookup.
• Test Reference — how to read streak, luster, cleavage versus fracture, and the acid test.

YOUR COLLECTION
• Log the specimens you find with a photo, a linked field-guide entry, the locality, the date, and optional coordinates.
• Record your own hardness and specific-gravity measurements.
• Everything is stored locally on your device.

PRIVATE AND OFFLINE BY DESIGN
• Works everywhere — the quarry, the trail, the plane — with no signal.
• No account, no sign-in, no subscription.
• No analytics, no tracking. Your photos and collection never leave your device.

Specimen photographs are sourced from Wikimedia Commons under public-domain, CC0, CC-BY and CC-BY-SA licenses, with full per-image attribution inside the app.

A note on photo identification: Lithify does not pretend an AI can name a rock from a single picture. Automated mineral photo-ID is unreliable, so the honest, accurate path is the dichotomous key and the diagnostic field tests — with the reference library always one tap away to confirm.

Buy it once. Own it forever. Take it anywhere.


## Version history (last 1 release)

### 1.0 — 2026-07-29

No release notes.

## More apps by Robert Corbin

- [Daily Word Journey](https://appshunter.io/ios/app/daily-word-journey/id6761548266)
- [Hush Secret Text](https://appshunter.io/ios/app/hush-secret-text/id6761658175)
- [Renew Guard](https://appshunter.io/ios/app/renew-guard/id6761755447)
- [Receipt to PDF](https://appshunter.io/ios/app/receipt-to-pdf/id6761782025)
- [Route Your Pay](https://appshunter.io/ios/app/route-your-pay/id6761783719)
- [Tip Arbiter](https://appshunter.io/ios/app/tip-arbiter/id6761786879)

All apps by Robert Corbin: https://appshunter.io/developer/1890247992

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*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 2026-08-11.*