Guides

25 guides from Rock Identifier.

• Best Rock Identifier Apps: 6 Compared

  We put our own app, Rock Identifier – Crystals ID, side by side with five of the most popular rock identifier apps on the App Store, and compared them on how well each explains what you found, and what happens to your finds afterwards.

• Crystal shapes and their scientific names

  This page lists common crystal shapes (habits) and the scientific names used by mineralogists, with clear descriptions you can use when photographing or scanning a sample for identification.

• How to differentiate a gem from a mineral

  This guide shows clear, practical steps to tell a gem from a mineral using simple observations, a photo or a scanner, and when to seek a finder or expert for value and recognition.

• How to estimate gemstone value accurately

  This guide explains practical steps to estimate a gemstone's worth using visual checks, simple tools, and market comparison. Follow each step to improve recognition of a gem or crystal and to form a defensible estimate of value.

• How to identify a gem by refractive index

  This page explains how to use refractive index to identify a gem, with step-by-step instructions, necessary tools, and common limitations for gemstones and minerals.

• How to identify a gemstone by its colour

  Colour is one of the fastest clues to a gemstone’s identity, but it is only one property. This guide explains how to use hue, tone and visible features to narrow possibilities, what checks to run next, and when to seek further testing.

• How to identify a meteorite from a rock photo

  You can often rule out common rocks from a photo and spot key clues to whether a specimen might be a meteorite. A common surface feature to look for is Fusion crust: thin dark rind, visible as a smooth, dark outer skin on many meteorites.

• How to identify a mineral by its streak

  The streak test is a simple, reliable way to help identify a mineral by the color of its powdered form. It works for many common minerals and can be done with minimal equipment; you can record results with a photo or scanner and compare them to reference samples to check recognition and worth.

• How to identify agate and jasper rocks

  This page explains clear, practical steps to tell agate from jasper in hand specimens and photos, using visual clues and simple tests you can do without a lab.

• How to identify amethyst crystal

  Practical steps to confirm whether a purple specimen is amethyst, with tests you can do in the field or at home and tips on common lookalikes and value indicators.

• How to Identify Igneous Rocks: Granite, Basalt, Obsidian & Pumice

  To identify igneous rocks, check grain size, glassy or vesicular texture, color and visible crystals such as feldspar, then confirm with simple field tests. Igneous rock identification starts with these observations.

• How to identify crystal cleavage and fracture

  This page shows how to tell cleavage from fracture by looking at break surfaces, reflections, and repeat patterns. You will learn safe visual checks, clear signs to note in a photo, and short examples you can compare to a gemstone, crystal or mineral sample.

• How to identify fossils in rocks

  Simple, practical steps to spot and document fossils in rock outcrops, riverbeds, and loose stones. Learn what to look for, how to record finds, and how to protect specimens.

• How to identify granite versus marble rocks

  Clear, practical checks you can do in the field or at home to tell granite from marble by eye, touch and simple tests. These steps use texture, hardness and reaction to acid to separate the two rock types.

• How to identify metamorphic rocks

  Practical steps to recognize metamorphic rocks by sight and simple tests. The guide covers visual cues, common types, field checks, and how to document samples for further study.

• How to identify obsidian and volcanic glass rocks

  This guide explains clear, testable traits to tell obsidian and other volcanic glass from common rocks and man-made glass. Read the visual, tactile and simple field tests before using a scanner or photo tool for confirmation.

• How to identify pyrite versus gold mineral

  Simple, repeatable tests let you tell pyrite from gold using sight, a streak plate, and a few handheld checks. This guide explains clear steps you can do in the field or at home to assess crystals, nuggets, and samples.

• How to identify quartz crystal varieties

  Practical, step-by-step methods to tell different quartz crystals apart using only observation, simple field checks, and good photos. This guide covers color clues, crystal form, common inclusions, and how to record features that affect recognition and worth.

• How to identify sedimentary rocks by layers

  Layers are the primary clue for identifying sedimentary rocks. This guide shows clear, practical steps to read bedding, spot common features, and confirm rock types in the field.

• How to tell if a rock contains gold value

  Simple, practical steps you can use in the field to check whether a rock might contain gold value, including visual signs, basic tests, and when to seek professional recognition.

• How to test if diamond is real gemstone

  Practical, step-by-step checks you can do at home to assess whether a stone is a real diamond gem. The guide covers simple visual checks, basic household tests, and when to use a scanner or seek professional recognition.

• Identify my rock by photo

  Take clear, well-lit photos and include a scale and multiple views so a finder or expert can begin recognition of your rocks, minerals, gems or crystals from the images.

• Rock identifier by photo

  A rock identifier by photo uses a camera image to suggest likely matches for rocks, minerals, gemstones and crystals. The system compares color, texture and shape in the picture to reference specimens and returns candidate identifications with notes on confidence and next steps.

• What is Mohs hardness for quartz mineral

  Quartz is a common mineral used as a gemstone and in industry; its Mohs hardness 7 and Chemical formula SiO2 are quick identifiers when you examine crystals, rocks or gem samples with a photo or a field finder.

• What is the worth of raw gemstone

  Raw gemstone worth depends on physical traits, market demand and provenance. Read how professionals judge value and the steps you can take to estimate worth yourself.