laurionite

Formula compatibility

Record analytical support for PbCl(OH), distinguishing measured constituents from inferred hydroxyl content.

1. Which measurements support PbCl(OH), and which parts of the formula remain inferred? measurement
2. Were the analyses taken from a laurionite candidate crystal or from a mixed bulk sample? boundary

Polymorph resolution

Laurionite and paralaurionite require structural discrimination; their orthorhombic and monoclinic structures are related through ordering. [Structural study](https://www.cambridge.org/core/journals/mineralogical-magazine/article/abs/crystal-structure-of-paralaurionite-and-its-OD-relationships-with-laurionite/A088C24E6E7DEAD5B98767023240099D)

1. Which diffraction observations establish orthorhombic laurionite rather than monoclinic paralaurionite? measurement
2. Do unexplained reflections or structural disorder require a mixed or unresolved phase assignment? boundary

Habit and surface record

Record crystal dimensions, transparency, color, habit, and any face indexing as observations tied to a specific crystal.

1. What dimensions, habit, transparency, and surface features does the candidate crystal exhibit? measurement
2. Could an observed coating, intergrowth, or adjacent crystal account for the apparent identification features? boundary

Property measurement validity

Distinguish properties measured on an isolated candidate crystal from values affected by matrix, porosity, or preparation.

1. Which measured physical properties independently support the identification, and what uncertainty accompanies them? measurement
2. Would a hardness or density measurement consume or damage material needed for more decisive diffraction analysis? action

Laurionite fraction

Record laurionite abundance only within the sampled volume and the capabilities of the analytical method.

1. What laurionite phase fraction was measured, using which method and uncertainty estimate? measurement
2. Does the result describe a selected crystal, a powder aliquot, or the whole specimen? boundary

Intergrowth and matrix

Map identified neighbouring phases and distinguish inclusions, substrates, and later surface deposits.

1. Which associated phases are independently identified, and where are they relative to laurionite? measurement
2. Which mapped region can provide a representative laurionite measurement with minimal contribution from adjacent material? action

Origin evidence

Reported settings include saline alteration of lead-bearing slag and oxidized lead deposits; an individual specimen needs its own supporting record. [Handbook of Mineralogy](https://www.handbookofmineralogy.org/pdfs/laurionite.pdf)

1. What evidence places this specimen in a deposit, slag-alteration, or synthetic setting? provenance
2. Does the origin statement describe observed context or an interpretation inferred from the locality name? boundary

Label and analysis link

Maintain specimen identifiers, label history, sampling locations, and analytical references together.

1. Which collection or field records substantiate the locality and specimen identity? provenance
2. Can every analytical aliquot be traced to its parent specimen and sampled crystal or region? provenance

Water and treatment response

Reported water solubility increases from cold to hot water, so aqueous treatment requires compatibility evidence. [Handbook of Mineralogy](https://www.handbookofmineralogy.org/pdfs/laurionite.pdf)

1. What previous washing, heating, mounting, or chemical treatment has the specimen undergone? provenance
2. What evidence supports the proposed treatment's compatibility with laurionite and its associated phases? action

Operation-specific assessment

Record the proposed operation, physical form, applicable handling documentation, and unresolved requirements for the lead-containing material.

1. Will the proposed operation leave crystals intact or generate powder, liquid residues, or heated material? action
2. Which applicable assessment supports the handling and residue-management measures for that operation? provenance
3. What minimum sample can resolve the identification while preserving a documented reference portion? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of laurionite this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these identifiers and schemes hold for the sense of laurionite this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of laurionite this model covers, and on what evidence? provenance

Typical measurements

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these typical measurements hold for the sense of laurionite this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of laurionite this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of laurionite this model covers, and on what evidence? provenance