Chalcedony: Grading & Localities
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Chalcedony Grading and Locality Atlas
Chalcedony Quality, Origin, Treatment, and Variety: A Lapidary Guide to Reading the Stone Well
Chalcedony is graded by what the eye can verify and the hand can preserve: colour, glow, band rhythm, inclusion depth, polish, structural integrity, treatment history, and locality support. Because blue chalcedony, agate, carnelian, chrysoprase, bloodstone, moss agate, drusy chalcedony, onyx, and fire agate excel in different ways, the most reliable evaluation begins with variety-specific standards rather than a single universal grade.
Grading Context
What a Chalcedony Grade Should Communicate
Chalcedony does not have a single international grading system. Letter grades such as A, AA, and AAA may appear in trade language, but they are only useful when the criteria behind them are stated. A more dependable description explains why a piece is fine, ordinary, collectible, or study-grade: what the colour does, how light moves through the stone, whether the pattern is crisp, whether the polish is clean, whether the structure is stable, and whether treatments or locality claims are documented.
The first rule is to identify the category before judging the grade. A blue chalcedony cabochon is not evaluated the same way as a Laguna agate slice, chrysoprase cabochon, drusy chalcedony plate, fire agate dome, bloodstone palm, or moss agate scene. Each variety has its own form of excellence.
Lapidary Grade
Useful before cutting. It judges whether the colour, pattern, and structure will survive sawing, shaping, polishing, drilling, or setting.
Gem Grade
Used for finished cabochons, beads, carvings, jewellery stones, and matched pairs. It emphasizes surface finish, shape, translucence, colour balance, and structural integrity.
Specimen Grade
Used for slices, nodules, geodes, drusy plates, and collector material. Pattern, rarity, size, completeness, locality, and natural presentation become more important.
Documentation Grade
Used when origin or treatment matters. A credible label, collection record, or lab note can strengthen a piece, but only when the visible material supports the claim.
A good grade should be repeatable. Another informed reader should be able to inspect the same stone and understand why the description was chosen.
Quality Framework
A Core Rubric for Chalcedony Evaluation
The following rubric provides a strong baseline for finished chalcedony. The weights can be adjusted by variety. Fire agate requires extra emphasis on play-of-colour and contour cutting. Chrysoprase requires extra emphasis on green saturation and translucence. Banded agate requires extra emphasis on pattern sharpness and orientation. Drusy chalcedony requires extra emphasis on crystal stability.
| Factor | Fine to Exceptional Quality | Warning Signs | Inspection Method |
|---|---|---|---|
| Colour and Tone | Natural-looking colour with strong variety character: calm blue, crisp apple green, warm carnelian, clean red-on-green bloodstone, or balanced agate contrast. | Neon uniform colour, dull muddy zones, dye pooling, harsh artificial saturation, or colour that ignores the stone’s natural structure. | Use neutral daylight first, then a second light source. Inspect edges, drill holes, fractures, and recesses. |
| Translucence and Glow | Soft waxy glow, clean edge translucence, depth under backlight, or appropriate opacity for flint, chert, and jasper-like material. | Chalky patches, cloudy dead zones, dull interiors, overly thin pale edges, or a centre that fails to carry light. | Use diffused front light, low side light, and cool backlight. Rotate slowly rather than judging from one angle. |
| Pattern and Structure | Sharp fortification bands, readable waterlines, balanced inclusions, crisp dendrites, broad fire-agate colour, or well-distributed bloodstone spots. | Blurred banding, broken composition, muddy inclusion masses, sparse red spotting, isolated fire, or pattern lost through poor orientation. | View both close and at arm’s length. A strong pattern should remain readable without magnification. |
| Polish and Workmanship | Even high polish, clean bevels, balanced dome shape, smooth drilling, stable drusy surface, and a cut that honours the stone’s best feature. | Orange-peel texture, pits, scratches, flat cabochon domes, undercut inclusions, rough backs, uneven drill holes, or shedding druse. | Use low side light and magnification. Rotate to reveal scratches, pits, waviness, and polish breaks. |
| Integrity and Stability | Minimal fractures, stable edges, sound matrix, strong bead drilling, and no hidden weakness that threatens normal handling. | Cracks reaching edges, unstable vugs, crumbly matrix, broken drusy crystals, friable backs, or repairs hidden by polish. | Inspect the back, edge, matrix contact, drill holes, thin bands, and any transition between chalcedony and host rock. |
| Treatment Clarity | Natural colour when supported, or plainly disclosed heat, dye, sugar-acid blackening, coating, stabilization, or impregnation. | Vague enhancement language, undisclosed bright dye, colour bleeding, coated drusy sold as natural, or black onyx described as untreated without support. | Ask for treatment history. Look for colour in cracks, drill holes, pits, and porous layers. |
| Origin Support | Credible source documentation, old labels, collector notes, invoices, direct collection history, or visual character that matches an attributed source. | Famous locality names used without evidence, impossible locality claims, or broad regional names applied to inflate importance. | Record what is confirmed, what is attributed, and what is unknown. Do not let a name outrank the stone itself. |
Use clear tiers such as exceptional, fine, good, and study grade. Each tier should be tied to visible criteria rather than implied authority.
Inspection Method
A Repeatable Chalcedony Evaluation Workflow
Chalcedony rewards slow looking. Many of its best features are subtle: waxy glow, edge translucence, inclusion depth, band rhythm, and quiet colour shifts. A repeatable workflow prevents dramatic lighting or one beautiful angle from doing all the grading work.
Establish the Variety
Identify whether the piece is blue chalcedony, agate, carnelian, chrysoprase, bloodstone, moss agate, plume agate, fire agate, drusy chalcedony, onyx, sardonyx, flint, or another related material.
View Colour Under Neutral Light
Begin with diffused daylight or neutral lamp light. Record body colour before backlighting, magnification, or dramatic photography lighting.
Use Side Light for Surface Quality
Low side light reveals scratches, orange-peel texture, pits, uneven polish, shallow domes, undercut inclusions, and weak bevel work.
Use Backlight for Internal Structure
Cool backlight reveals translucence, waterlines, hidden fractures, band density, iris potential, and the true internal life of blue chalcedony and carnelian.
Check Edges, Backs, and Drill Holes
These areas often reveal dye concentration, cracks, incomplete polish, friable matrix, hidden fill, unstable vugs, or structural weakness.
Evaluate the Whole Composition
For agates and scenic material, judge balance and readability. A strong piece should hold its structure from more than one viewing distance.
Record Treatment and Origin Separately
Treatment status and origin support should be written as separate notes. A beautiful stone can be treated; a famous locality can still produce ordinary material.
Variety Standards
Quality Standards by Chalcedony Variety
Variety-specific grading is the heart of chalcedony evaluation. The same word “fine” should mean different things for different stones: serenity in blue chalcedony, rhythm in agate, glow in carnelian, freshness in chrysoprase, drama in bloodstone, depth in moss agate, stable sparkle in drusy, and broad internal colour in fire agate.
Blue Chalcedony
Fine blue chalcedony carries a soft, even blue to blue-grey body colour with misted translucence and a waxy inner calm.
- Exceptional: even cool hue, clean translucence, strong polish, minimal clouding.
- Good: pleasant colour with slight zoning or mild internal haze.
- Lower: chalky body, weak polish, dull grey patches, cracks, or suspicious electric-blue dye.
Banded Agate
Banded agate quality rests on rhythm, contrast, orientation, and the way bands carry through the face of the cut.
- Exceptional: sharp fortifications, balanced contrast, fine translucence, stable edges.
- Good: clear banding with minor smudged zones or small interruptions.
- Lower: blurred bands, muddy sections, fractures through the main pattern, or poorly oriented cutting.
Carnelian and Sard
Carnelian is judged by warm orange-red glow; sard by deeper red-brown body colour, steadiness, and polish.
- Exceptional: rich warm colour, luminous backlight, even body, clean polish.
- Good: mild blotching or zoning with appealing warmth and stable structure.
- Lower: dull brown dead zones, obvious dye, weak translucence, fractures, or rough drilling.
Chrysoprase and Chrome Chalcedony
Green chalcedony is strongest when the colour is fresh, saturated, translucent, and not overwhelmed by brown matrix.
- Exceptional: crisp apple, mint, or chrome green with fine translucence and minimal veining.
- Good: attractive green with slight clouding, modest matrix, or softer saturation.
- Lower: chalky pale colour, heavy brown veining, poor polish, or dyed green substitute material.
Bloodstone
Bloodstone needs the relationship between green ground and red iron markings to read clearly.
- Exceptional: dark to rich green body with distinct red spots across the face.
- Good: mixed green base and moderate red markings with sound polish.
- Lower: muddy brown-green body, sparse red, smeared spotting, or weak contrast.
Moss, Plume, and Dendritic Agate
Scenic chalcedony succeeds when inclusions feel suspended, dimensional, and composed rather than muddled.
- Exceptional: clear base, crisp inclusions, strong depth, balanced scene, high contrast.
- Good: pleasing inclusion structure with some haze or uneven density.
- Lower: cloudy body, confused inclusion mass, poor contrast, or fractures cutting through the best scene.
Fire Agate
Fire agate depends on play-of-colour, correct contour cutting, and preservation of the thin iridescent layers.
- Exceptional: broad bright fire with reds, greens, golds, and possible blues across a well-shaped dome.
- Good: localized but lively colour patches with sound cutting.
- Lower: dull bronze-only sheen, tiny isolated fire, overcut layers, or damaged surface.
Drusy Chalcedony
Drusy quality relies on crystal uniformity, sparkle, adhesion, matrix stability, and honest coating disclosure.
- Exceptional: tight even microcrystals, lively sparkle, stable surface, clean edges.
- Good: mixed crystal size or small bare areas without significant shedding.
- Lower: crumbly crystals, patchy surface, unstable base, or coated colour presented as natural.
Onyx and Sardonyx
Layered chalcedony is judged by clean parallel bands, contrast, carving potential, polish, and disclosure.
- Exceptional: crisp layers, strong contrast, sound structure, clean polish.
- Good: usable band contrast with mild irregularity or softer finish.
- Lower: weak layers, dye concentration in cracks, poor carving orientation, or confusion with banded calcite.
Enhancement and Disclosure
Treatments, Enhancements, and Practical Red Flags
Chalcedony has a long history of treatment because its porosity and banded structure can accept colour. Treatment does not make a stone unworthy; hidden treatment makes a description weak. The goal is to identify what can be known and state it clearly.
| Treatment | Common Use | Visual Clues | Clear Description |
|---|---|---|---|
| Heat | Carnelian, sard, and some agates, often to deepen or regularize iron-based colours. | Stronger red-orange tone, more even warmth, reduced grey or brown patches. | Heat-treated carnelian; carnelian, treatment not confirmed. |
| Dye | Bright blue, green, purple, pink, red, and black chalcedony, especially beads and decorative agates. | Colour pooling in drill holes, cracks, pits, backs, and porous zones; colour that looks too uniform for the pattern. | Dyed chalcedony; dyed agate; colour-treated chalcedony. |
| Sugar-Acid Blackening | Traditional darkening of porous chalcedony layers, especially black onyx effects. | Dense black bands, dramatic contrast, little natural translucence in dark zones. | Treated black onyx; black onyx, treatment common. |
| Staining or Smoke Treatment | Darkening porous bands or emphasizing contrast. | Uneven darkening that follows pores, cracks, and recesses rather than clean growth bands. | Stained agate; smoke-treated chalcedony. |
| Stabilization or Impregnation | Improving polish, durability, or colour saturation in porous or fractured material. | Plastic-like gloss in pits, filled fractures, resin sheen, or unusually sealed porous zones. | Stabilized chalcedony; resin-impregnated agate. |
| Metallic Coating | Rainbow drusy finishes and novelty surfaces. | Iridescent colour that sits on crystal faces instead of coming from internal structure. | Coated drusy chalcedony; titanium-coated drusy. |
Dye Clues
- Colour concentration in drill holes or cracks.
- Neon blue, aqua, purple, pink, green, or black with little natural zoning.
- Uniform colour that crosses bands without respecting structure.
Stability Clues
- Cracks reaching the edge or crossing the dome.
- Crumbly matrix, unstable vugs, or loose drusy crystals.
- Filled pits, glossy fracture seams, or uneven backs.
Naming Clues
- Architectural “onyx” is often banded calcite, not chalcedony.
- Opaque chalcedony may overlap with jasper and flint terminology.
- Famous locality names should match both appearance and documentation.
World Localities
Notable Chalcedony Localities and Their Signatures
Chalcedony forms widely, but some localities are known for distinctive material. Locality can add historical and collector interest, but the stone must still stand on visible quality. A weak piece from a famous source is still weak; a fine piece from an unknown source remains fine.
Namibia
Signature: Blue Lace Agate with fine sky-blue lace, pale banding, soft translucence, and delicate rhythm.
- Evaluation focus: clean blue tone, band delicacy, fracture control, and absence of chalky dead zones.
Botswana
Signature: smoky grey, peach, cream, brown, and soft pinkish fortification bands in polished agate.
- Evaluation focus: tight band rhythm, silky polish, peach-grey contrast, and pattern continuity.
Brazil and Uruguay
Signature: large basalt-hosted agate nodules, geodes, quartz druse centres, fortification bands, and abundant slice material.
- Evaluation focus: dye disclosure, slice thickness, clean druse, stable edges, and genuine translucence.
India
Signature: Deccan carnelian and agate nodules, historically important bead-grade material, warm red-orange chalcedony, and heat-treated carnelian traditions.
- Evaluation focus: body glow, clean drilling, even warmth, fracture control, and heat-treatment clarity.
Mexico
Signature: Laguna, Coyamito, Crazy Lace, and other sharply patterned agates with vivid bands, lace, and dramatic structure.
- Evaluation focus: razor-sharp bands, locality support, pattern density, fractures, and cut orientation.
United States
Signature: Lake Superior Agate, Montana Moss Agate, Arizona Fire Agate, Oregon thundereggs, Fairburn Agate, and many regional styles.
- Evaluation focus: regional match, pattern strength, fire quality, dendrite clarity, and thunderegg centring.
Australia
Signature: chrysoprase from Queensland and Western Australia, along with diverse agates and jasper-like microcrystalline quartz.
- Evaluation focus: green saturation, translucence, matrix amount, polish, and separation from serpentine, prehnite, and dyed substitutes.
Turkey and Anatolia
Signature: soft blue chalcedony, historically resonant through the name’s traditional association with ancient Chalcedon near the Bosphorus.
- Evaluation focus: natural blue tone, waxy glow, translucence, polish, and dye concerns.
Germany and Central Europe
Signature: historic agate cutting and dyeing traditions, especially associated with Idar-Oberstein and carved chalcedony work.
- Evaluation focus: workmanship, treatment clarity, carving orientation, and whether the location is a cutting centre rather than the source of the rough.
United Kingdom, France, and Poland
Signature: chalk-hosted flint, striped flint, chert nodules, and opaque microcrystalline silica with ancient toolstone significance.
- Evaluation focus: correct material naming, sharp striping, polish contrast, and historical context when relevant.
Madagascar
Signature: plume agates, moss agates, colourful chalcedony nodules, and scenic inclusion material.
- Evaluation focus: clear bases, high-contrast plumes, scene balance, fractures, polish, and locality support.
Global Sources
Signature: chalcedony forms worldwide in cavities, veins, nodules, fractures, replacement zones, and silica-rich fluid systems.
- Evaluation focus: visible quality, honest origin language, treatment clarity, and structure over prestige names.
Reference
Fast Reference Tables for Variety and Locality
| Variety | Primary Quality Cues | Secondary Quality Cues | Common Concerns |
|---|---|---|---|
| Blue Chalcedony | Even cool hue, waxy glow, soft translucence. | Clean polish, gentle body depth, balanced cabochon shape. | Dye, chalkiness, dull grey patches, fractures. |
| Banded Agate | Sharp bands, rhythm, contrast, cut orientation. | Translucence, slice thickness, stable druse centre. | Dye, fractures, muddy bands, weak edge stability. |
| Carnelian and Sard | Warm red-orange or red-brown colour, glow, polish. | Evenness, clean drilling, historic material context. | Dull brown zones, dye, fractures, undisclosed heat. |
| Chrysoprase | Apple-green saturation, translucence, freshness. | Low matrix, polish, stable body. | Chalkiness, brown veining, dyed substitutes. |
| Bloodstone | Dark green ground with clear red spots. | Balanced spotting, polish, low muddy zoning. | Sparse red, weak contrast, brown base. |
| Moss and Plume Agate | Clear base, crisp inclusions, scenic depth. | Composition, contrast, stable cut. | Cloudy body, fractured scenes, confused inclusion mass. |
| Fire Agate | Broad play-of-colour and careful contour cutting. | Colour variety, dome balance, preserved surface layers. | Bronze-only sheen, tiny fire patches, overcut layers. |
| Drusy Chalcedony | Even microcrystals, sparkle, stable adhesion. | Clean edges, matrix balance, natural colour or clear coating disclosure. | Shedding crystals, patchy druse, undisclosed coatings. |
| Locality | Typical Material | Signature Look | Evaluation Focus |
|---|---|---|---|
| Namibia | Blue Lace Agate. | Fine pale-blue lace, delicate bands, soft translucence. | Band delicacy, colour calmness, fractures, chalky areas. |
| Botswana | Botswana Agate. | Grey, peach, cream, and brown fortification bands. | Band rhythm, silky polish, contrast, continuity. |
| Brazil and Uruguay | Geodes, agate slices, fortification agates, drusy centres. | Large nodules, vivid bands, quartz-lined cavities. | Dye disclosure, edge stability, slice thickness, druse condition. |
| India | Carnelian and agate nodules. | Warm orange-red chalcedony and bead-grade material. | Glow, heat history, drilling, fracture control. |
| Mexico | Laguna, Coyamito, Crazy Lace, and related agates. | Sharp bands, ornate lace, vivid pattern, collector-grade contrast. | Locality evidence, band precision, cut orientation, fractures. |
| United States | Lake Superior Agate, Montana Moss Agate, Arizona Fire Agate, Oregon thundereggs. | Regional iron-red bands, mossy dendrites, iridescence, and nodule interiors. | Locality match, fire quality, pattern strength, centred cuts. |
| Australia | Chrysoprase and diverse agates. | Apple-green nickel chalcedony and regional microcrystalline quartz. | Green saturation, translucence, matrix amount, substitute separation. |
| Turkey and Anatolia | Blue chalcedony. | Soft even blue with waxy internal glow. | Natural tone, translucence, polish, dye concerns. |
| Madagascar | Plume, moss, and scenic agates. | High-contrast inclusions and colourful chalcedony nodules. | Scene clarity, base transparency, polish, fracture control. |
| Europe | Flint, chert, historical cut agates, and onyx traditions. | Striped flint, chalk nodules, carved and dyed chalcedony work. | Correct naming, historical context, treatment clarity. |
Origin Language
How to Describe Locality and Provenance Responsibly
Locality can add richness to chalcedony, but it should not be guessed into certainty. A precise origin statement tells the reader what is known, what is probable, and what remains open.
Confirmed Origin
Use when the source is supported by reliable documents, original labels, direct collection history, lab reports, or a credible chain of custody.
Example: Laguna Agate, Chihuahua, Mexico, from a labelled collector parcel.
Attributed Origin
Use when the visual character strongly suggests a known source, but documentation is incomplete. This is honest when the stone resembles the locality but certainty is not available.
Example: Attributed Botswana Agate, based on colour and banding style.
Unknown Origin
Use when locality cannot be supported. The stone can still be excellent. It simply should not carry a famous source name without evidence.
Example: Banded agate, locality unknown.
Visible truth is stronger than unsupported prestige. If origin is uncertain, describe the stone by observable features: blue translucent chalcedony, red-orange carnelian, dendritic moss agate, black-white layered chalcedony, or banded agate with unknown locality.
Preservation
Care, Storage, and Display for Graded Chalcedony
Chalcedony is durable compared with many decorative stones, but quality depends on polish, edge condition, treatment stability, and structural soundness. Dyed, coated, stabilized, drusy, porous, or heavily fractured pieces require more conservative handling than untreated solid agate or carnelian.
Recommended Care
- Clean most untreated chalcedony with mild soap, lukewarm water, and a soft cloth.
- Use a soft brush for carved details and an air bulb for drusy surfaces.
- Dry drilled beads, slices, and porous material thoroughly after cleaning.
- Store polished pieces separately from harder stones, metal edges, and abrasive grit.
- Use padded supports for slices, geodes, thin slabs, and fragile drusy edges.
Best Avoided
- Do not soak dyed, coated, stabilized, porous, or unknown-treatment material.
- Do not use steam or ultrasonic cleaning on fractured, dyed, coated, drusy, or matrix-rich pieces.
- Do not expose dyed chalcedony to prolonged strong sunlight or solvents.
- Do not stack polished slices without padding.
- Do not treat architectural “onyx” as chalcedony unless the mineral identity is confirmed.
| Cabochons | Protect the dome from abrasive grit. Wipe after wear and store away from harder gems and metal edges. |
|---|---|
| Beads | Check drill holes for dye, cracking, wear, and roughness. Dry stringing channels thoroughly after cleaning. |
| Slices | Support edges and avoid flexing. Use cool LED backlighting for display and avoid heat near dyed or stabilized material. |
| Geodes | Dust with a soft brush or air bulb. Avoid soaking if the matrix is friable, iron-stained, repaired, or unstable. |
| Drusy | Handle by the base, not the crystal face. Avoid scrubbing, soaking, rough packaging, and pressure on crystal points. |
| Fire Agate | Protect contour-polished layers. Abrasion and poor recutting can damage the colour-bearing surface. |
Reflective Practice
Merchant’s Measure: A Discernment Practice for Honest Evaluation
This short practice turns evaluation into a moment of attention. It is symbolic rather than diagnostic. Its purpose is to slow impulse, steady the eye, and support a description that can stand without exaggeration.
Merchant’s Measure
Use a small banded agate, blue chalcedony, or clear chalcedony beside the piece being evaluated.
- Place the stone on a plain white, grey, or matte black surface.
- Write the seven factors: colour, glow, pattern, polish, integrity, treatment, origin.
- Breathe slowly for seven counts before beginning inspection.
- Examine the piece under neutral light, side light, and cool backlight.
- Record what is known, what is visible, and what remains uncertain.
- Finish with one concise description based only on supportable evidence.
End by writing a description that includes variety, visible quality, treatment status when known, and origin certainty. If the sentence depends on drama, simplify it until the stone itself carries the claim.
Questions
Chalcedony Grading and Localities FAQ
Are A, AA, and AAA chalcedony grades standardized?
No. Those grades are vendor shorthand and vary widely. They are useful only when paired with a clear rubric explaining colour, translucence, pattern, polish, integrity, treatment, and origin.
What is the most important grading factor for chalcedony?
The key factor depends on the variety. Blue chalcedony depends on even colour and glow; agate on pattern sharpness; chrysoprase on green saturation and translucence; bloodstone on red-on-green contrast; fire agate on broad play-of-colour; drusy chalcedony on sparkle and surface stability.
Does locality always increase value?
No. Locality matters when it is documented and the stone shows strong quality for that source. Famous origin does not compensate for poor colour, weak polish, broken structure, or unsupported treatment claims.
How can dyed chalcedony be recognized?
Look for neon colour, dye concentration in drill holes, cracks, pits, backs, and low areas, or colour that ignores natural banding. Bright blue, aqua, pink, purple, green, red, and black chalcedony should be inspected carefully.
Is heat-treated carnelian acceptable?
Yes. Heating carnelian is traditional and common. The important issue is disclosure when treatment is known. When history is unknown, wording such as “carnelian, treatment not confirmed” is appropriate.
Is black onyx always natural?
No. Much commercial black onyx is treated, often by dyeing or sugar-acid blackening. Gemological onyx is layered chalcedony, while architectural “onyx” is often banded calcite or travertine.
What makes a high-grade agate slice?
A high-grade agate slice has crisp bands, good contrast, stable thickness, clean edges, attractive translucence, and a polish that reveals the structure. A clean druse centre can add interest when it is stable and well presented.
What makes chrysoprase high grade?
High-grade chrysoprase usually has saturated apple to mint green colour, fine translucence, minimal brown veining, stable structure, and clean polish. Chalkiness, heavy matrix, dye, and substitute confusion lower reliability.
What is the safest wording when origin is uncertain?
Use “attributed” only when the stone strongly resembles a known source but lacks complete documentation. Otherwise, describe the visible material: “banded agate, locality unknown” or “blue chalcedony, origin not confirmed.”
How should graded chalcedony be stored?
Store polished chalcedony separately from harder stones and abrasive grit. Use padding for slices, geodes, drusy pieces, and cabochons. Keep dyed, coated, or stabilized material away from long soaking, solvents, strong heat, and prolonged strong sunlight.
Closing Perspective
The Best Grade Lets Chalcedony Tell the Truth Beautifully
Chalcedony grading is strongest when it is specific. Blue chalcedony asks for calm colour and waxy glow. Agate asks for band rhythm. Carnelian asks for warmth and inner light. Chrysoprase asks for fresh green translucence. Bloodstone asks for red marks that stand clearly on green ground. Moss and plume agate ask for readable depth. Fire agate asks for living colour preserved by careful cutting. Drusy chalcedony asks for stable sparkle. Locality adds another layer only when it is handled honestly. The finest description is not the loudest one; it is the one in which colour, structure, origin, treatment, and beauty all agree.