feldspar
Enable an agent to recognise feldspar-bearing material, assess its mineral identity and condition, and judge suitability for a proposed use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise feldspar-bearing material, assess its mineral identity and condition, and judge suitability for a proposed use.
Feldspar is a group of rock-forming framework aluminosilicate minerals whose principal compositional series extend between potassium, sodium and calcium end members, represented by KAlSi3O8, NaAlSi3O8 and CaAl2Si2O8.
It can be Select identification tests that distinguish feldspar phases from accompanying or alteration minerals.; Classify a specimen or lot to the level supported by its analytical evidence.; Compare measured phase composition and bulk chemistry with an intended glass or ceramic feedstock specification.; Assess whether further sampling, sorting, separation, or milling is needed before use.; Flag handling decisions that require material-specific dust, crystalline-silica, or safety-document evidence..
Distinguishing features
Test whether mineralogical and chemical evidence supports a feldspar identity rather than relying on colour or a supplier's trade name.
Use observed cleavage, hardness, and crystal habit to distinguish candidate feldspar from quartz, then resolve ambiguous grains with analytical evidence.
Distinguish alkali feldspar from plagioclase using composition together with appropriate crystallographic or optical evidence; record unresolved cases explicitly.
Check whether a nominal feldspar specimen is a single mineral grain, an intergrowth, an altered grain, or a mixed commercial concentrate.
Distinguish feldspar from visually similar feldspathoids or alteration products through phase identification rather than appearance alone.
Scope
+ Feldspar-group identity and distinctions among alkali feldspar, plagioclase, and unresolved feldspar material
+ Mineral composition, compositional variation, and evidence supporting identification
+ Crystal structure, intergrowths, grain texture, and physical identification observations
+ Weathering, alteration, inclusions, and accompanying minerals
+ Commercial feldspar grade, processing suitability, and handling constraints tied to measured material properties
- Complete classification and geological history of host rocks
- Independent models of individual feldspar species or varieties
- Mine design, mineral rights, and deposit economics
- Finished ceramic bodies, glass products, and their manufacturing specifications
- Complete models of accompanying quartz, mica, clay, or other minerals
Characteristics
- Identity resolution
- feldspar group only | alkali feldspar | plagioclase | identified species | unresolved Prevents a broad group name from implying a specific mineral composition or structure.
- Evidence-bearing sample relationship
- specimen or lot linked to sampled grains, analytical subsamples, and identification records Shows whether an identification applies to one grain or represents the material being assessed.
- Feldspar endmember composition
- Or-Ab-An molar proportions where applicable, with analytical basis and uncertainty Supports compositional classification without confusing mineral chemistry with bulk-lot chemistry.
- Bulk oxide composition
- mass % of reported oxides, including SiO2, Al2O3, K2O, Na2O, CaO, and relevant impurities; reporting basis stated Supports evaluation against glass or ceramic feedstock requirements.
- Mineral phase proportions
- mass % or volume % feldspar phases and accompanying minerals, with method and detection limits Separates feldspar abundance from chemical composition and exposes mixed-material limitations.
- Crystal and intergrowth character
- identified structural form, twinning, zoning, exsolution texture, or unresolved; evidence recorded Helps interpret mineral identity, within-grain variability, and limits of bulk measurements.
- Alteration condition
- unaltered within observation limits | partly altered | extensively altered | unassessed; products and extent recorded Changes how confidently the original mineral can be identified and whether material remains suitable for use.
- Particle size and liberation
- particle-size distribution in µm or mm; liberation proportion with stated size fraction and method Informs separation, milling, sampling, and dust-control decisions.
- Application test response
- fired colour, shrinkage, softening or melting behaviour under a specified formulation and temperature-time schedule Avoids treating all feldspar grades as having one universal processing response.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.feldspar
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 16 findings · 26 questions.
Feldspar identity and boundaries Establishes what the feldspar designation refers to and how precisely it is supported.
The registry entry names a mineral group, while observations and commercial labels may refer to a species, grain, or mixed lot.
Mineral identification
Connects a feldspar identification to observations and diagnostic analyses.
Supported identification level
Record the narrowest feldspar identity justified by evidence, including competing identifications.
- Does the available evidence establish feldspar only, alkali feldspar, plagioclase, or a particular species? definition
- Which observations or analyses distinguish the material from quartz, feldspathoids, and alteration minerals? measurement
Specimen and lot boundary
Separates the mineral concept from the physical material to which an assessment applies.
Assessed material unit
Identify whether the assessment concerns a grain, specimen, rock constituent, concentrate, or commercial powder.
- What physical unit is being called feldspar, and which accompanying material is included in that unit? boundary
- How were the analysed grains or subsamples selected, and which specimen or lot do they represent? provenance
Composition and crystal character Captures feldspar chemistry and structural features needed to interpret mineral identity.
A feldspar label alone cannot establish endmember proportions, structural form, or chemical uniformity.
Mineral and bulk chemistry
Keeps grain-scale feldspar composition distinct from whole-material analysis.
Composition with analytical basis
Record measured chemistry, its sampling scale, and the assumptions behind any calculated endmember proportions.
- What feldspar grain compositions and Or-Ab-An proportions are supported, and how were they measured or calculated? measurement
- Which reported chemical values describe feldspar itself, and which describe the bulk mixture? boundary
Structure and intergrowths
Records crystallographic identity and heterogeneity within or between feldspar grains.
Resolved crystal character
Attach evidence to structural assignments, twinning, zoning, and any interpreted exsolution texture.
- Which diffraction, optical, or other observations support the assigned feldspar structural form? measurement
- Do zoning or intergrowths require separate phase or spatial measurements before a single composition can represent this material? action
Assemblage, texture, and alteration Describes how feldspar occurs with other minerals and how its present condition affects assessment.
Mixed phases, incomplete liberation, and alteration can make a nominal feldspar material behave differently from its identified grains.
Phase associations and liberation
Records accompanying minerals and their physical association with feldspar.
Feldspar abundance and separability
Establish phase proportions and whether unwanted minerals occur as separate grains, coatings, or inclusions.
- What proportions of feldspar, quartz, mica, clay, and other detected phases occur, on what measurement basis? measurement
- At the assessed particle size, which accompanying minerals are liberated and which remain attached or enclosed? measurement
Alteration and grain integrity
Records replacement, surface change, and damage relevant to feldspar identification or use.
Present feldspar condition
Distinguish observed alteration products and fractures from assumptions based on appearance.
- Which alteration products, coatings, or fractures are observed, and how extensive are they? measurement
- Does the observed condition require reclassification, additional testing, or exclusion from the proposed application? action
Grade, performance, and handling Connects a feldspar lot to a particular application and its material-specific handling evidence.
Commercial suitability depends on measured grade and processing response, while handling requirements depend on the actual mixture and physical form.
Application-specific grade
Evaluates feldspar feedstock against explicit glass, ceramic, or other application requirements.
Demonstrated grade suitability
Link acceptance decisions to chemical, particle-size, impurity, and application-test results.
- Which limits on alkali balance, iron-bearing impurities, particle size, and other properties define the intended grade? definition
- What tests under the intended formulation and thermal schedule demonstrate acceptable processing behaviour? measurement
- Should this lot be accepted, blended, beneficiated, or held for further testing against that specification? action
Material identity and dust evidence
Associates supplier identity and handling information with the actual feldspar material.
Lot-specific handling basis
Record applicable safety documentation and evidence about dust and accompanying crystalline silica without assigning one blanket classification to the mineral group.
- Which supplier identifiers and safety documents apply to this material, grade, and jurisdiction? provenance
- What evidence establishes crystalline-silica content and airborne dust exposure for the proposed crushing, milling, or transfer operation? measurement
- Which handling controls are required by the applicable documents and operation-specific assessment? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This description covers the mineral group; industrial feldspar products may be mixtures requiring their own composition and impurity specifications.
- Physical-property ranges are approximate group-level values; identify the constituent mineral and composition before assigning precise constants.
- Chemical registry identifiers, hazard classifications and exposure limits should be checked for the specific supplied material; none are asserted here.
- Which of these check these first hold for the sense of feldspar this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Alkali feldspar
- Plagioclase feldspar
- Which of these kinds and varieties hold for the sense of feldspar this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- International Mineralogical Association mineral nomenclature - Group and constituent mineral names - Feldspar denotes a mineral group rather than a single chemical substance; constituent names include orthoclase, microcline, sanidine, albite and anorthite.
- Which of these identifiers and schemes hold for the sense of feldspar this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Flux and alumina source in ceramic bodies and glazes.
- Alumina and alkali source in glass manufacture.
- Mineral filler in paints, plastics and other manufactured materials.
- Identification and classification of igneous and metamorphic rocks.
- Selected optically attractive varieties used as gemstones and ornamental materials.
- Which of these real-world use hold for the sense of feldspar this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Mohs hardness - Approximately 6-6.5 - Mohs scale
- Density - Approximately 2.55-2.76, depending on composition - g/cm³
- Angle between principal cleavage planes - Approximately 90 - degree
- Which of these typical measurements hold for the sense of feldspar 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.
- Crushing, grinding and handling powders generate dust that can irritate eyes and the respiratory tract.
- Commercial feldspar may contain quartz; respirable crystalline silica contamination requires separate assessment.
- Brittleness and two prominent cleavage directions make crystals susceptible to chipping and fracture.
- Weathering and hydrothermal alteration can replace feldspar with clay minerals or other secondary minerals.
- Iron-bearing impurities and variable alkali content can cause unwanted colour or inconsistent firing behaviour in ceramics.
- Which of these failure modes and hazards hold for the sense of feldspar this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Deposit geology produces regional differences in potassium-to-sodium ratio, calcium content and associated quartz, mica and iron-bearing impurities.
- Commercial grades and purchasing specifications vary among suppliers and markets; a feldspar trade name alone does not establish composition or purity.
- Which of these regional variation hold for the sense of feldspar 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.
- Quartz - Quartz is SiO2, has Mohs hardness 7 and lacks feldspar's two prominent cleavage directions.
- Feldspathoid - Feldspathoids are distinct framework silicate minerals with lower silica content relative to comparable feldspars.
- Clay mineral - Clay minerals commonly have sheet structures and may form through feldspar alteration; they are not feldspar varieties.
- Granite - Granite is a rock composed of multiple minerals, commonly including feldspar and quartz; feldspar is a mineral group.
- Nepheline syenite - Nepheline syenite is a rock containing feldspar and nepheline that can serve similar industrial functions, rather than a feldspar mineral.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of feldspar this model covers, and on what evidence? provenance
What the second pass must settle
- Which authoritative mineral nomenclature and classification references should govern feldspar species assignments and unusual compositions?
- Does an existing Vercy world model already own the feldspar-group concept, requiring this registry entry to link to it?
- Which analytical methods and uncertainty thresholds are sufficient for the intended decisions when zoning, intergrowths, or alteration complicate identification?
- Which application-specific feldspar grade specifications and thermal test methods should be adopted for the initial supported uses?
- Which commercial identifiers, safety classifications, and exposure requirements apply to the actual supplied mixtures and jurisdictions?