Mohs Scratch Book

Mohs Scratch Book is an offline-first mineral identification notebook for rockhounds and geology students who work one hand sample at a time. No camera ID, no GPS—just structured field science from your own scratch tests, streak, lustre, and cleavage. COLD START ON THE BENCH Open to a fullscreen specimen-card deck: a slate-grey field bench of mineral cards. Each card shows nickname, provisional ID, Mohs band chip, streak swatch, lustre tag, and a confidence pip. Seed cards (quartz pebble, calcite cleavage, unknown basalt chip) get you logging immediately. PROPERTY WORKSHEET PER SPECIMEN Tap a card to run the full worksheet. Enter nickname, date found, typed locality, rock host notes, and free-form field remarks. Log Mohs hardness against reference steps 1–10 (talc through diamond) with observed scratch/result chips and an effective hardness range on the card face. Record streak-plate colour with named swatches (white, grey, red-brown, green-black, none) plus an optional typed colour note. Pick lustre (metallic, vitreous, pearly, earthy) and cleavage or fracture (perfect/imperfect planes, conchoidal or uneven). Lock your own mineral name, alternate suspects, and a 1–5 confidence rating that updates the deck pip. COMPARE, REFERENCE, FIND Resolve look-alikes with side-by-side compare of two cards—hardness band, streak, lustre, and cleavage at a glance. Use the built-in Mohs scale reference sheet with common reference minerals and typical field substitutes (penny, nail, glass, steel file as typed tips). Filter and search the collection by hardness band, lustre, streak colour, confidence, or identification text—all local queries. OFFLINE BY DESIGN Cards are Room-backed on device. Export a share-sheet summary of one specimen’s properties. Set default confidence and deck sort order in preferences. Built for collectors and students who identify minerals from real scratch sessions, not photo guesses.

Recent changes:
Initial production release of Mohs Scratch Book.

First release: fullscreen specimen-card deck with seed mineral cards. Log Mohs scratch tests, streak colour, lustre, and cleavage per hand sample. Lock your own ID and confidence, compare two cards side by side, search locally, and export offline specimen summaries. Built-in Mohs reference included.

Mohs Scratch Book is an offline-first mineral identification notebook for rockhounds and geology students who work one hand s…