Lithify: Geology Field Guide
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| Rating | Price | |||
|---|---|---|---|---|
| United Arab Emirates | <1%0 | — | AED 12.99 $3.54 | |
| Afghanistan | <1%0 | — | $2.99 | |
| Antigua And Barbuda | <1%0 | — | $2.99 | |
| Anguilla | <1%0 | — | $2.99 | |
| Albania | <1%0 | — | $3.99 | |
| Armenia | <1%0 | — | $3.99 | |
| Angola | <1%0 | — | $2.99 | |
| Argentina | <1%0 | — | $2.99 | |
| Austria | <1%0 | — | €2.99 $3.46 | |
| Australia | <1%0 | — | A$4.99 $3.54 |
Description
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.