clarkeite

Reference definition

Record the adopted formula, structural reference, and nomenclatural authority separately from specimen observations.

1. Which mineralogical authority and version define clarkeite for this identification? definition
2. Does the evidence identify natural clarkeite, a related synthetic phase, or an unresolved sodium uranium compound? boundary

Matched chemistry and structure

Require chemical and structural results to refer to the same domain or a demonstrably representative sample.

1. Which diffraction features support clarkeite, and which alternative phases were tested? measurement
2. Were the sodium and uranium measurements obtained from the domain producing the assigned diffraction pattern? provenance

Empirical formula basis

Preserve analytical totals, normalization assumptions, and evidence for assigning elements to clarkeite.

1. What are the measured Na, U, K, Ca, and Pb contents within identified clarkeite domains? measurement
2. Which normalization and oxidation-state assumptions produce the reported empirical formula? definition
3. Could an apparent substitution instead reflect unresolved inclusions or adjacent phases? boundary

Hydration evidence

Record structural-water and hydroxyl interpretations together with specimen conditioning.

1. Which measurements distinguish structural water and hydroxyl from surface moisture? measurement
2. Was hydrogen measured directly or inferred from charge balance or analytical deficit? provenance
3. Could drying, vacuum exposure, or heating have changed the material before characterization? boundary

Phase map

Record spatially resolved assignments and uncertainty at contacts or below analytical resolution.

1. Where are clarkeite, residual uraninite, and other identified phases located within the specimen? measurement
2. What fraction of the analyzed material is clarkeite, and how was that fraction estimated? measurement

Origin and replacement evidence

A published formation interpretation is oxidation-related replacement of pegmatitic uraninite; evaluate its applicability specimen by specimen. [Finch and Ewing, 1997](https://doi.org/10.2138/am-1997-5-620).

1. Which locality and collection records trace this fragment to its parent specimen? provenance
2. Which observed textures support a replacement sequence, and which parts of that sequence remain inferred? boundary

Integrity and order

Describe fractures, loose material, and diffraction quality without assigning an untested cause.

1. Does the specimen contain friable clarkeite-bearing regions or detached particles? measurement
2. Do broadened or missing reflections indicate poor crystallinity, mixed phases, or an unresolved analytical limitation? boundary

Replacement products and change

Record identified secondary phases and repeat measurements before attributing changes to aging or environmental exposure.

1. Which secondary phases are independently identified at altered clarkeite boundaries? measurement
2. What observations establish a change since the previous examination? provenance
3. Which proposed analysis could modify the phase, and what baseline observations are needed first? action

Measurement context

Attach instrument, calibration, background, geometry, and measurement date to each reported result.

1. What dose rate was measured at specified distances and orientations, with what background and instrument response? measurement
2. What evidence addresses removable contamination and loose uranium-bearing particles? measurement
3. If activity was calculated, what isotope and decay-chain assumptions were used? provenance

Use eligibility

Record the basis for storage, display, transfer, or sampling decisions without assigning universal permissions to clarkeite.

1. Is the proposed activity intact-specimen observation, destructive sampling, storage, display, or transfer? action
2. Which current institutional and jurisdictional requirements apply to this specimen's measured properties and proposed activity? action
3. What additional measurements or documented controls are required before that activity can proceed? 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 clarkeite 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 clarkeite 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 clarkeite 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 clarkeite this model covers, and on what evidence? provenance