Reference library · Mineral world · Field & laboratory
Rocks, minerals & fossils
Geological identification is a chain from field context through observable properties to tests of increasing specificity. Habit, texture, grain relationships, hardness, streak, cleavage and density can narrow a candidate; mineral chemistry, diffraction or spectroscopy can settle questions that a photograph cannot. Fossils add anatomy, stratigraphy and literature. The resources here keep those roles distinct: naming authorities, diagnostic measurements, community discovery, stratigraphic context and sample infrastructure are not interchangeable.
A field photograph may support a broad rock class, fossil group or distinctive mineral, but colour and locality are rarely enough for species-level mineral identification or a fine fossil determination. Weathering, mixtures, treatments and lookalikes make image-only claims fragile. Name the tests performed and retain raw spectra, diffraction, chemistry or measurements. If laboratory confirmation is required but absent, report the candidate or material class and the test that would resolve it.
Before you reach for an atlas
Record the characters first.
Matching a photograph against a memory is how misidentifications happen. Working through
these in order gives you a description that someone else can check — and that stays
useful even if the determination later changes.
Field and geological context
Record the material in place, its relationship to surrounding units and the precision and legality of the locality.
Include orientation, bed or unit, host rock, contacts, associated minerals or fossils and whether the sample was found loose. Do not expose sensitive collectable localities publicly.
Scale, habit and texture
Photograph fresh and weathered surfaces with scale and describe grain size, fabric, habit and relationships.
A close-up without a whole-sample view hides context. Record whether grains or crystals are visible, intergrown, layered, vesicular, clastic, foliated or altered.
Physical properties
Record hardness method, streak, cleavage, fracture, lustre, density estimate, magnetism and reaction only when safely tested.
State the reference materials and uncertainty. Surface coatings, weathering and mixed samples can change results, and destructive tests should not be used on valuable or irreplaceable material.
Fossil anatomy and taphonomy
Record orientation, preserved structures, completeness, deformation, matrix and whether the specimen is a body fossil, trace, mould or cast.
Photograph all diagnostic views and avoid preparing away contextual matrix. Stratigraphic position and preservation can be as important as visible anatomy.
Analytical evidence
Retain instrument, method, calibration, standards, raw files, processing and uncertainty for every analysis.
A spectrum or age without acquisition and quality-control context is not independently checkable. Preserve sample identifiers and links between subsamples, analyses and the parent object.
These are the observations. Standards covers the vocabularies
that carry them into a record — including Darwin Core for biological occurrences,
REMBI and OME for imaging, and ABCD-EFG for geological material — while each observation
profile records its own method-specific context. Prepare a
contribution covers what to keep alongside the files themselves.
Resources
Grouped by the question you are asking.
A resource can appear under more than one heading. Each entry states who maintains it,
what it is best for, and where it stops being reliable.
Nothing here matches that.
Clear the filter, or search the whole library from the library index.
Describe what you observed
Character guides and controlled terminology, so your description means the same thing to the next reader.
RRUFF research project, originating at the University of Arizona
Measured Raman, X-ray diffraction, chemistry and related reference data linked to documented mineral samples.
Best for
Comparing laboratory measurements with reference spectra or diffraction data rather than relying on appearance.
Limits
Species and sample coverage are incomplete, and RRUFF is not the mineral-naming authority. The rebuilt service still marks some functions as unfinished.
Coverage
Global mineral reference samples represented by available analytical datasets.
Reuse
RRUFF citation and site terms apply to data and downloads.
Hudson Institute of Mineralogy with an expert-moderated volunteer community
A very large community resource for mineral, rock, meteorite and locality discovery, associations, photographs and references.
Best for
Generating candidates from habit and associations and finding locality-specific literature or comparable photographs.
Limits
Community-curated rather than a nomenclatural authority. Corroborate names with IMA and occurrences with surveys or literature; photographs alone do not identify a specimen.
Coverage
Global minerals, rocks, meteorites and collecting localities, uneven by contributor activity.
Reuse
Database and media terms are mixed; check the individual record or image before reuse.
Contributing
Browsing is open; an account is required for contributions and some tools.
Included as the geological community exception because its moderation, locality depth and evidence links are unusually useful; it remains a discovery source, not the final authority.
Primary museum records and research datasets spanning palaeontology, mineralogy and other natural-history collections, often with stable identifiers and media.
Best for
Finding a documented museum specimen or dataset to compare and citing its holding institution and stable record.
Limits
Represents Natural History Museum holdings and digitisation, not all collections. Records and historical identifications can be incomplete or revised.
Coverage
Natural History Museum collections and published datasets across natural-history disciplines.
Reuse
Licence is stated per dataset; core collection data are commonly CC0 while media and research datasets may differ.
Database on Geochemical, Environmental and Biological Reference Materials
International Association of Geoanalysts with current infrastructure partners
Certified, recommended and published values for rock, mineral, glass, solution and other analytical reference materials.
Best for
Documenting calibration and quality assurance against an appropriate reference material and comparing published values.
Limits
Reference materials only, not field specimens. Users must distinguish certified, recommended and compiled values and retain database and material versions.
Coverage
International geochemical, environmental and selected biological analytical reference materials.
Reuse
International Association of Geoanalysts and database citation terms apply.
Database Open Research pass ·
Resolve the name or identifier
Authorities that settle an accepted biological or mineral name, astronomical designation or other stable identifier.
International Mineralogical Association Commission on New Minerals, Nomenclature and Classification
The authoritative list of accepted mineral names, status, formulae and nomenclatural changes maintained by the IMA commission responsible for mineral naming.
Best for
Checking whether a mineral name is approved, renamed, discredited or otherwise qualified, with the list version retained.
Limits
Not an identification key, occurrence database or image library. An accepted name does not show that a sample belongs to that species.
Coverage
Globally recognised mineral species and IMA nomenclatural status.
Reuse
IMA and CNMNC reuse terms apply; cite and retain the dated list or update used.
RRUFF research project, originating at the University of Arizona
Measured Raman, X-ray diffraction, chemistry and related reference data linked to documented mineral samples.
Best for
Comparing laboratory measurements with reference spectra or diffraction data rather than relying on appearance.
Limits
Species and sample coverage are incomplete, and RRUFF is not the mineral-naming authority. The rebuilt service still marks some functions as unfinished.
Coverage
Global mineral reference samples represented by available analytical datasets.
Reuse
RRUFF citation and site terms apply to data and downloads.
Hudson Institute of Mineralogy with an expert-moderated volunteer community
A very large community resource for mineral, rock, meteorite and locality discovery, associations, photographs and references.
Best for
Generating candidates from habit and associations and finding locality-specific literature or comparable photographs.
Limits
Community-curated rather than a nomenclatural authority. Corroborate names with IMA and occurrences with surveys or literature; photographs alone do not identify a specimen.
Coverage
Global minerals, rocks, meteorites and collecting localities, uneven by contributor activity.
Reuse
Database and media terms are mixed; check the individual record or image before reuse.
Contributing
Browsing is open; an account is required for contributions and some tools.
Included as the geological community exception because its moderation, locality depth and evidence links are unusually useful; it remains a discovery source, not the final authority.
Meteoritical Society Nomenclature Committee, hosted by the Lunar and Planetary Institute
The official database of meteorite names, approval status, classification, find locality, initial description and type repository.
Best for
Checking an official meteorite name and following its classification and repository information.
Limits
Provisional, doubtful and early classifications need care; classifications can change and mass or collection details can be incomplete. It does not authenticate a newly found stone.
Coverage
Officially named meteorites and related nomenclatural records worldwide.
Reuse
Meteoritical Society and Lunar and Planetary Institute citation and use terms apply.
International, multi-institutional community of palaeobiological researchers
A global, literature-linked research database of fossil occurrences, taxonomy, stratigraphy and analytical data.
Best for
Checking the published occurrence and stratigraphic context of a fossil candidate and tracing the source literature.
Limits
Contributor-driven and taxonomically dynamic. It is not a museum specimen catalogue or final taxonomic authority, and coverage follows the entered literature.
Coverage
Global fossil occurrences and palaeobiological literature, uneven by group and region.
Reuse
CC BY 4.0 for database content; cite the database and contributing references.
Contributing
Public search, API and downloads are open; contribution requires an approved account.
Data repository Open API Research pass ·
Use the right method
Published field, preparation, imaging, measurement and analysis methods, with their limitations and safety requirements.
RRUFF research project, originating at the University of Arizona
Measured Raman, X-ray diffraction, chemistry and related reference data linked to documented mineral samples.
Best for
Comparing laboratory measurements with reference spectra or diffraction data rather than relying on appearance.
Limits
Species and sample coverage are incomplete, and RRUFF is not the mineral-naming authority. The rebuilt service still marks some functions as unfinished.
Coverage
Global mineral reference samples represented by available analytical datasets.
Reuse
RRUFF citation and site terms apply to data and downloads.
Database on Geochemical, Environmental and Biological Reference Materials
International Association of Geoanalysts with current infrastructure partners
Certified, recommended and published values for rock, mineral, glass, solution and other analytical reference materials.
Best for
Documenting calibration and quality assurance against an appropriate reference material and comparing published values.
Limits
Reference materials only, not field specimens. Users must distinguish certified, recommended and compiled values and retain database and material versions.
Coverage
International geochemical, environmental and selected biological analytical reference materials.
Reuse
International Association of Geoanalysts and database citation terms apply.
Database Open Research pass ·
Place it in context
Occurrence, stratigraphic, catalogue and archive services that situate a record in space, time and literature.
International Mineralogical Association Commission on New Minerals, Nomenclature and Classification
The authoritative list of accepted mineral names, status, formulae and nomenclatural changes maintained by the IMA commission responsible for mineral naming.
Best for
Checking whether a mineral name is approved, renamed, discredited or otherwise qualified, with the list version retained.
Limits
Not an identification key, occurrence database or image library. An accepted name does not show that a sample belongs to that species.
Coverage
Globally recognised mineral species and IMA nomenclatural status.
Reuse
IMA and CNMNC reuse terms apply; cite and retain the dated list or update used.
Hudson Institute of Mineralogy with an expert-moderated volunteer community
A very large community resource for mineral, rock, meteorite and locality discovery, associations, photographs and references.
Best for
Generating candidates from habit and associations and finding locality-specific literature or comparable photographs.
Limits
Community-curated rather than a nomenclatural authority. Corroborate names with IMA and occurrences with surveys or literature; photographs alone do not identify a specimen.
Coverage
Global minerals, rocks, meteorites and collecting localities, uneven by contributor activity.
Reuse
Database and media terms are mixed; check the individual record or image before reuse.
Contributing
Browsing is open; an account is required for contributions and some tools.
Included as the geological community exception because its moderation, locality depth and evidence links are unusually useful; it remains a discovery source, not the final authority.
Meteoritical Society Nomenclature Committee, hosted by the Lunar and Planetary Institute
The official database of meteorite names, approval status, classification, find locality, initial description and type repository.
Best for
Checking an official meteorite name and following its classification and repository information.
Limits
Provisional, doubtful and early classifications need care; classifications can change and mass or collection details can be incomplete. It does not authenticate a newly found stone.
Coverage
Officially named meteorites and related nomenclatural records worldwide.
Reuse
Meteoritical Society and Lunar and Planetary Institute citation and use terms apply.
A research aggregation linking geological maps, stratigraphic columns, harmonised unit names and fossil occurrences through web tools and an API.
Best for
Placing a field observation in broad map and stratigraphic context and finding the original geological source to consult.
Limits
An academic aggregator rather than a naming authority. Global coverage is uneven and the original map, survey or publication should be cited for a record.
Coverage
Global with strongest depth where map and column sources have been integrated.
Reuse
Macrostrat data are generally CC BY 4.0 while source-provider terms remain attached.
International, multi-institutional community of palaeobiological researchers
A global, literature-linked research database of fossil occurrences, taxonomy, stratigraphy and analytical data.
Best for
Checking the published occurrence and stratigraphic context of a fossil candidate and tracing the source literature.
Limits
Contributor-driven and taxonomically dynamic. It is not a museum specimen catalogue or final taxonomic authority, and coverage follows the entered literature.
Coverage
Global fossil occurrences and palaeobiological literature, uneven by group and region.
Reuse
CC BY 4.0 for database content; cite the database and contributing references.
Contributing
Public search, API and downloads are open; contribution requires an approved account.
Primary museum records and research datasets spanning palaeontology, mineralogy and other natural-history collections, often with stable identifiers and media.
Best for
Finding a documented museum specimen or dataset to compare and citing its holding institution and stable record.
Limits
Represents Natural History Museum holdings and digitisation, not all collections. Records and historical identifications can be incomplete or revised.
Coverage
Natural History Museum collections and published datasets across natural-history disciplines.
Reuse
Licence is stated per dataset; core collection data are commonly CC0 while media and research datasets may differ.
Hudson Institute of Mineralogy with an expert-moderated volunteer community
A very large community resource for mineral, rock, meteorite and locality discovery, associations, photographs and references.
Best for
Generating candidates from habit and associations and finding locality-specific literature or comparable photographs.
Limits
Community-curated rather than a nomenclatural authority. Corroborate names with IMA and occurrences with surveys or literature; photographs alone do not identify a specimen.
Coverage
Global minerals, rocks, meteorites and collecting localities, uneven by contributor activity.
Reuse
Database and media terms are mixed; check the individual record or image before reuse.
Contributing
Browsing is open; an account is required for contributions and some tools.
Included as the geological community exception because its moderation, locality depth and evidence links are unusually useful; it remains a discovery source, not the final authority.
A research aggregation linking geological maps, stratigraphic columns, harmonised unit names and fossil occurrences through web tools and an API.
Best for
Placing a field observation in broad map and stratigraphic context and finding the original geological source to consult.
Limits
An academic aggregator rather than a naming authority. Global coverage is uneven and the original map, survey or publication should be cited for a record.
Coverage
Global with strongest depth where map and column sources have been integrated.
Reuse
Macrostrat data are generally CC BY 4.0 while source-provider terms remain attached.
Database Open API Research pass ·
Safety
Some observations and preparations need specialist safeguards.
Hazards change with the field, site, material and equipment. Follow the requirements of
the source method, manufacturer, facility and relevant authority, and do not improvise
a procedure whose controls or training you do not have.
Unknown geological material can be hazardous
Do not taste, lick, heat, grind or create dust from an unknown mineral, rock, fossil preparation or industrial material. Fibrous minerals, silica dust, heavy metals, arsenic minerals, radioactive material and historic treatments may not be obvious from appearance. Keep material contained and seek an equipped geological or conservation laboratory when a test would release dust or fumes.
Locality does not grant permission to collect
Land ownership, protected areas, fossil and mineral heritage laws, Indigenous authority and export rules can all restrict collecting. Record an observation in place when permission is absent or unclear, and generalise public coordinates for vulnerable fossil sites, culturally sensitive places and high-value mineral occurrences.
This is orientation, not laboratory training, and it is not a substitute for the safety
instruction and supervision your institution requires.
Corrections
Know this field better than this page does?
The most valuable correction is not another link. It is knowing that an entry's stated limit
is wrong, or that a resource practitioners rely on is missing.
