BOU010 · identification + care literacy
Learn to separate what you can responsibly describe from what needs a source record, gemological testing or qualified laboratory examination. This route does not authenticate, appraise, determine provenance, diagnose treatment or identify a stone from a photograph.
Observation versus determination
Choose an evidence type to see what it can support. The complete framework remains visible below without JavaScript.
Complete no-JS framework
Never promote a weaker evidence class into a stronger conclusion simply because the stone looks convincing.
Does not establish natural/lab-grown status, treatment, geographic origin, authenticity or value.
Record who made the statement, the date, exact locality/treatment wording and any supporting paperwork. Do not rewrite an undocumented statement as verified provenance.
A museum or collection record can support accession identity and stated provenance for that documented object. A similar-looking stone does not inherit that record.
GIA states that its Colored Stone Identification Report can identify natural versus laboratory-grown material and name detectable treatments. GIA evaluates opal but does not grade it.
Terminology
These terms are supported by museum and gemological sources. They describe material or market categories; they do not let BOU identify an unknown stone from an image.
Opal that displays play of colour.
Sources · BOU-SRC-011
Opal without play of colour; it can occur in many colours and transparencies.
Sources · BOU-SRC-011
An Australian miners’ term used for common opal on the opal fields.
Sources · BOU-SRC-011
Queensland boulder opal is associated with retained ironstone host or matrix; the host relationship is part of the material, not proof that an unknown lookalike came from a particular field.
Sources · BOU-SRC-001 · BOU-SRC-011
Laboratory-made opal material exists and may look convincing to an unpracticed observer. Visual resemblance alone is not a reliable separation method.
Sources · BOU010-SRC-003
A different material can be made to imitate opal appearance; GIA documents glass, including Slocum stone, as an opal imitation.
Sources · BOU010-SRC-004
GIA lists oil, wax or plastic impregnation and sugar/smoke surface modifications among opal treatment categories. A treatment cannot be safely diagnosed from a short visual checklist.
Sources · BOU010-SRC-001 · BOU010-SRC-002
Fracture lines associated with opal stability problems; GIA notes high heat and sudden temperature change as fracture risks.
Sources · BOU010-SRC-001
Conservative care
BOU010 gives only source-grounded, non-destructive care guidance. It does not turn care actions into authenticity tests.
Use warm, soapy water for routine cleaning; this is the safe cleaning method stated by GIA.
Scope · general opal care guidance; mounted jewellery may have additional setting-specific considerations
Sources · BOU010-SRC-001
Protect opal from scratching, chipping, high heat and sudden temperature changes.
Scope · general stability/toughness guidance
Sources · BOU010-SRC-001
Treat sudden or extreme humidity/temperature change as a cracking risk and preserve storage history when condition is important.
Scope · museum watchpoint; not a universal guarantee of cracking or stability
Sources · BOU010-SRC-005
Do not use scratch, flame, impact, hazardous chemical, solvent or other destructive home tests to try to authenticate an unknown opal.
Scope · BOU safety/evidence policy derived from the need for laboratory identification rather than destructive home testing
Sources · BOU010-SRC-002 · BOU010-SRC-003 · BOU010-SRC-004
Research ledger
Text evidence is cited; external source imagery is not copied into BOU.
Gemological Institute of America · gemological_care_guidance
Text used for care evidence; GIA imagery is not reproduced in BOU.
Gemological Institute of America · gemological_laboratory_scope
Text used for laboratory-scope evidence; no external media copied.
Gemological Institute of America · gemological_synthetic_reference
Text used for synthetic terminology; page imagery is not reproduced in BOU.
Gemological Institute of America · gemological_imitation_reference
Text used for imitation/simulant terminology; page imagery is not reproduced in BOU.
Australian Museum · museum_gemology_education
Text used for opal terminology and stability context; Australian Museum imagery is not reproduced in BOU.
Gemological Institute of America · gemological_observation_reference
Text used for descriptive observation vocabulary; page imagery is not reproduced in BOU.
Continue through BOU
Use these released systems to inspect source-backed records, not to infer origin or value from appearance.
Question triage
The same visible stone can support a description while still leaving provenance, natural/laboratory-grown status, treatment and value unresolved.
Visible properties can be described without certifying identity.
Educational output only. This interaction does not issue an authenticity, treatment, origin or value certificate.
ICU / CONNECTED DISCOVERY
These are bounded editorial connections; paid placement does not influence them.
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