They call it BS Jade — it’s just Black Sheep Jade
The Stone of Heaven
What is Jade?
Known throughout history as “The Stone of Heaven,” jade is an umbrella term used to describe two distinct gem materials: nephrite, an amphibole-rich aggregate, and jadeite jade, a pyroxene-rich rock composed predominantly of the mineral jadeite. Source: GIA ↗
Those two materials are not varieties of one another. They come from different mineral families, they are built from different crystal architectures, and they arrive at their colors by different chemical routes. Almost every disagreement about jade begins with somebody not knowing which of the two is in their hand. Source: Mason-Kay ↗
What follows is a composition-first look at both: what each stone is actually made of, which minerals do the work, and why the purest jade of either kind has no color at all.
- Nephrite
- AmphiboleTremolite–actinolite series
- Jadeite jade
- PyroxeneJadeite–omphacite–kosmochlor
- Shared name
- JadeA trade umbrella, not a species
Part one
The Composition of Nephrite
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Nephrite consists primarily of interlocking amphibole minerals of the tremolite–actinolite series. The lightest nephrite is typically rich in tremolite, while increasing iron toward the actinolite–ferro-actinolite end of the series generally produces darker green to black material.
Tremolite acts as the foundational mineral; pure tremolite is a white, magnesium- and calcium-rich material. As iron increasingly substitutes for magnesium, the amphibole composition progresses from tremolite toward actinolite and, at still higher iron contents, ferro-actinolite. Source: IMA nomenclature ↗
A range of mineral inclusions and accessory minerals can naturally be present within the remaining structure. Some of the most common include:
- Magnetite
- Chromite
- Epidote
- Garnet
- Thulite
- Titanite
- Serpentine
- Talc
- Rutile
- Diopside
For example, prized Asian “mutton-fat” nephrite consists of an ultra-pure, tremolite-dominated matrix. Conversely, the deep, near-black nephrite deposits found in Asia (such as Guangxi) and Wyoming, USA, are heavily iron-dominated, running to actinolite and/or ferro-actinolite.
Ultimately, a nephrite stone’s final color is strongly influenced by the proportions and chemistry of these amphiboles.
- Mutton-fat nephrite
- TremoliteMagnesium-rich end of the series
- Guangxi & Wyoming black
- Iron-richActinolite and/or ferro-actinolite
- Standard specific gravity
- 2.88–3.03SG
The specific gravity of standard nephrite ranges between 2.88 and 3.03 SG, and iron-heavy material sits at the dense end of that range. Higher figures circulate for exceptionally dark nephrite; we are not quoting one until we can point to the analysis behind it.
Jadeite-bearing jade can occur within a pyroxene solid-solution system involving jadeite, omphacite, and kosmochlor. The proportions and chemistry of these pyroxenes, together with trace elements and accessory minerals, contribute to jadeite jade’s final color. Source: GIA ↗
Gem-quality jadeite jade is predominantly composed of the mineral jadeite, with accessory minerals such as omphacite, albite, amphibole, and chromite. In pyroxene nomenclature, approximately 80 mol.% jadeite is an important compositional boundary separating jadeite-dominant material from omphacite. Source: IMA nomenclature ↗
The remaining balance consists of minor accessory minerals and structural inclusions, which commonly include:
- Albite
- Zoisite
- Garnet
- Mica
- Quartz
- Omphacite
- Amphibole
- Chromite
- Solid-solution system
- Three end-pointsJadeite · omphacite · kosmochlor
- Nomenclature boundary
- ~80 mol.%Jadeite-dominant above; omphacite below
- Pure end-member
- NaAlSi2O6Colorless sodium aluminum silicate
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Part two
The Composition of Jadeite Jade
The three pyroxenes
- Jadeite — the sodium-aluminum end-member, colorless when pure.
- Omphacite — the calcium-magnesium-bearing neighbour; below roughly 80 mol.% jadeite the rock takes its name.
- Kosmochlor — the chromium-bearing member, and the source of some of the most vivid greens in the family.
Part three
The Secret of Color: Pure vs. Included Jade
A fascinating truth of the gem world is that in their absolute purest forms, neither stone possesses any colored pigment.
When nephrite closely approaches its tremolite-rich end-member, it presents as entirely white, while a pure jadeite end-member is completely colorless.
Pure nephrite
When nephrite nears its pure tremolite end-member, its tightly tangled crystal fibers naturally scatter light, giving it a creamy, opaque-to-translucent look resembling solid milk glass or rich lard.
Pure jadeite
Pure jadeite is colorless sodium aluminum silicate (NaAlSi2O6); natural gem-quality jadeite jade, however, commonly occurs as a fine-grained polycrystalline aggregate. In its pure end-member composition, jadeite is colorless, allowing light to pass through its crystalline structure and giving it a watery transparency known in the luxury trade as “Ice Jade.” Source: GIA ↗
Imperial jadeite
The principal high-value green in jadeite jade, and the green every other green ends up measured against.
GIA applies the name “Imperial jade” to the finest jadeite jade — almost transparent, with a vibrant emerald-green color — and ranks color as jadeite’s most important value factor, green as the most valuable color and lavender as the next. Intense color carries a substantial premium over lighter, weaker color. Source: GIA ↗
Transparency is counted as a separate factor, running from completely opaque to semitransparent. That is the question the watery material above belongs to: “ice” describes how light moves through a stone rather than what color the stone is. Worth understanding, and secondary to the green. Source: GIA ↗
Nephrite’s own palette
Nephrite keeps a quieter range: light to dark green, yellow, brown, black, gray or white, translucent to opaque, and generally more muted than jadeite. The lighter greens sit toward the tremolite end of the series; medium and darker greens follow the iron substitution described above. Source: GIA ↗
At the pale end sits “mutton-fat” white nephrite. Fine mutton-fat material is predominantly tremolite — the magnesium-rich end of the tremolite–actinolite series, and white when pure — which is what keeps it creamy rather than green. Source: IMA nomenclature ↗
What paints the stone
Therefore, it is the presence of chemical substitutions, trace elements, and mineral inclusions that paints both materials.
When iron substitutes into the tremolite matrix of nephrite, it shifts the amphibole composition toward actinolite and ferro-actinolite, systematically driving the stone into deep greens and ink blacks.
When chromium, iron, or manganese enter the pyroxene structure of jadeite — alongside inclusions of dark micas, quartz, green omphacite, or vibrant kosmochlor — they paint the stone with its legendary palette of vivid emerald greens, deep lavenders, icy blues, and rich charcoal hues.
Without these chemical variations and structural features, the vibrant world of colored jade would not exist.
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Reference
Nephrite and jadeite, side by side
| Property | Nephrite | Jadeite jade |
|---|---|---|
| Mineral family | Amphibole aggregate | Pyroxene aggregate |
| Series / system | Tremolite–actinolite–ferro-actinolite series | Jadeite–omphacite–kosmochlor solid solution |
| Pure end-member | Tremolite — white, magnesium- and calcium-rich | NaAlSi2O6 — colorless |
| Structure | Interlocking, tightly tangled crystal fibers | Fine-grained polycrystalline aggregate |
| Color driver | Iron substituting for magnesium | Chromium, iron, manganese, plus included pyroxenes |
| Pure appearance | Creamy and opaque-to-translucent — milk glass, lard | Watery transparency — the trade’s “Ice Jade” |
| Hardness (Mohs) | 6 – 6.5 | 6.5 – 7 |
| Specific gravity | 2.88 – 3.03 standard | 3.30 – 3.38 typical |
| Refractive index | 1.600 – 1.627 · spot 1.61 | 1.652 – 1.688 · spot 1.66 |
| Polished luster | Greasy, oily, waxy | Vitreous to sugary, often dimpled |
| Broken surface | Splintery and fibrous | Granular, with visible interlocking grains |
| Common accessories | Magnetite, chromite, epidote, garnet, thulite, titanite, serpentine, talc, rutile, diopside | Albite, zoisite, garnet, mica, quartz, omphacite, amphibole, chromite |
Home ground
California Jade
California has documented occurrences of both jade minerals — nephrite on the Monterey coast and in the Sierra foothills, jadeite in Coast Range serpentinite — and the older state-survey reports describe several of them in enough detail to still be useful in the field. California is not the only state with either mineral: the same volume that collects those reports also points to nephrite near Lander, Wyoming, and jadeite turns up in serpentinite-hosted subduction settings worldwide. Sources: CDMG SP 49 ↗ · Harlow & Sorensen ↗
- Clear Creek and the New Idria district, San Benito County — jadeite. Lens-shaped jadeite bodies enclosed in sheared serpentine, plus jadeite veins at the contacts of schist blocks, mapped in the canyon of Clear Creek. The best-described jadeite ground in the state. Albite and quartz keep jadeite company in these rocks: the first California report of jadeite described a quartz–albite–jadeite schist, and albite occurs inside the Clear Creek bodies themselves, both as blobs within the jadeite masses and as veinlets cutting them. Sources: CDMG SP 49 ↗ · Coleman (1961) ↗
- Pacheco Pass, central Diablo Range — jadeitic pyroxene. A geological locality rather than a lapidary one: jadeitic pyroxene in Franciscan metagraywacke, in company with lawsonite and glaucophane. Grains, not carving rough — but it is the assemblage that explains why jadeite exists in California at all. Sources: Ernst & Banno (1991) ↗ · McKee (1962) ↗
- Plaskett and Cape San Martin, Monterey County — nephrite. Nephrite in place in the sea cliffs, and as pebbles and boulders in the coves, along the stretch of coast between Plaskett and Cape San Martin. The cove holding the first nephrite found in place in California was named Jade Cove for exactly that reason. Source: CDMG SP 49 ↗
- Lewis Hill, near Porterville, Tulare County — nephrite. Specimens sent to the Division of Mines early in 1949 were identified as nephrite; by that October the lens was being worked by its discoverers, making it the first jade quarrying operation in the state. The lenses sit on Lewis Hill about two miles north of Porterville, and the one opened on the southeast flank reads as a metamorphosed inclusion in a serpentine sill. Medium to dark green, excellent translucency, and exceedingly tough to drill. Sources: CDMG SP 49 ↗ · Mineral Information Service (1950) ↗
California chrysoprase. Chrysoprase is a green variety of chalcedony — a quartz — and in its finest green it is the stone sold under the trade name “Australian jade.” Tulare County is a documented California locality: the old Deer Creek workings south of Porterville, carried by the USGS Mineral Resource Data System as the Deer Creek Chrysoprase pit with a recorded discovery year of 1897. Green, and Californian, and still not jade. Sources: Mason-Kay ↗ · USGS MRDS ↗ · Mineral Information Service (1950) ↗
Next
Recognizing them in nature
Composition explains what the stones are. It does not help much when you are standing in a creek bed holding a water-worn boulder with an oxidized rind. The field guide covers the checks that do work outdoors, in the order worth running them.
Finding Jade in Nature
Heft, the tap test, hardness, fracture surfaces, backlighting, weathering rinds and locality — plus the confirmations that need a bench.
Read the field guide →The lookalikes
Serpentine, vesuvianite, hydrogrossular, prehnite, chrysoprase and dyed quartzite — what gives each of them away.
See the table →Treatment codes
What A-, B- and C-jade mean, and the signs of bleaching, polymer impregnation and dye.
A, B and C →The house position
One big blended happy jadeitic family
Most of the jade trade sorts the stone into a hierarchy and arranges everything below the top of it in descending order of apology. That hierarchy throws away most of what is interesting about jade — because, as the composition shows, the color everyone is paying for comes from the substitutions and inclusions that a purist would call impurities. Source: GIA ↗
Every color, size and texture under the jade umbrella is welcome here: nephrite and jadeites, tremolite-white through ferro-actinolite black, icy jadeite–albite, omphacite, kosmochlor greens. What we insist on is that a stone be described for what it actually is.
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Sources & references
Where this comes from
Three different kinds of authority get blended together in most jade writing, and they are worth keeping apart. Where one mineral species stops and the next begins — tremolite into actinolite, jadeite into omphacite — is settled by IMA mineral nomenclature. Grading letters, fei cui and the rest of the market vocabulary are trade terminology, referenced here for comparison rather than used as this site’s classification system. What a seller in the United States is expected to disclose is a separate question again, and for that the FTC is the authority. Links below go to the original sources.
Gemological references
- GIA Gem Encyclopedia — Jade — mineral names and formulas for jadeite, nephrite and omphacite, with the refractive index, specific gravity and Mohs figures used in the comparison table above.
- GIA — Jade Description — GIA’s own statement that jade is a generic term covering nephrite, jadeite and, more recently, some green omphacite, plus its note on fei cui, the Chinese trade term now applied across much of Asia to jadeite, omphacite and kosmochlor.
- GIA — Jadeite Jade Quality Factors — how the trade ranks color, transparency and texture, including the “imperial jade” and old-mine/new-mine vocabulary.
- Hughes, R.W., et al., “Burmese Jade: The Inscrutable Gem,” Gems & Gemology, Spring 2000 — field study of the Myanmar jadeite mines covering geology, cutting, grading and treatment.
- Hsu, T., & Stone-Sundberg, J., “Nephrite Jade from Multiple Sources,” Gems & Gemology, Spring 2020 — currently producing nephrite localities and their consistent association with serpentinite host rocks at convergent margins.
- Mason-Kay — Technical Characteristics of Jadeite Jade — a specialist side-by-side table of specific gravity, refractive index, hardness, texture, luster and fracture for both jades, arrived at independently of GIA and in close agreement with it.
- Mason-Kay — Nephrite Jade vs. Jadeite Jade: What’s the Difference? — a U.S. jade specialist making the same point this page opens with: jade is an English trade term, not a scientific one, and it covers two different minerals.
Mineral nomenclature and scientific literature
- Morimoto, N., et al., “Nomenclature of pyroxenes,” American Mineralogist 73, 1123–1133 (1988) — the IMA pyroxene scheme, and the source of the 80 mol.% boundary separating jadeite-dominant material from omphacite in the Q–Jd–Ae classification. (PDF, Mineralogical Society of America.)
- Leake, B.E., et al., “Nomenclature of amphiboles,” American Mineralogist 82, 1019–1037 (1997) — the IMA amphibole scheme, which puts numbers on the iron substitution described above: tremolite at Mg/(Mg+Fe2+) of 0.9 and higher, actinolite from 0.5 to 0.9, ferro-actinolite below 0.5. (PDF, Mineralogical Society of America.)
- Harlow, G.E., & Sorensen, S.S., “Jade (Nephrite and Jadeitite) and Serpentinite: Metasomatic Connections,” International Geology Review 47, 113–146 (2005) — how each stone actually forms: nephrite by metasomatic replacement at serpentinite and dolomite contacts, jadeitite from sodium-aluminum-silicon-rich fluids under high-pressure, low-temperature subduction conditions.
Trade standards
- CIBJO — The Blue Books, including The Gemstone Book from the Coloured Stone Commission — the jewellery trade’s international nomenclature and disclosure standards. Adoption is voluntary; they are industry standards, not law.
U.S. advertising and disclosure
- FTC — Jewelry, Precious Metals, and Pewter Industries — the Jewelry Guides, 16 CFR Part 23, with the Commission’s notices and the 2018 revision.
- 16 CFR § 23.24 — Disclosure of treatments to gemstones — treatment should be disclosed where it is not permanent, where it creates special care requirements, or where it has a significant effect on the stone’s value.
- 16 CFR § 23.25 — Misuse of gemstone names — using the name of a precious or semi-precious stone for a product that is not in fact that mined stone is treated as unfair or deceptive — the ground under objections to trade names that borrow the word jade.
- 16 CFR § 23.26 — Misrepresentation as to varietal name — describing material with the wrong varietal name is likewise treated as deceptive.
The Jewelry Guides set out the Commission’s views on what would be deceptive under the FTC Act; by their own terms they confer no rights and do not bind the FTC or the public. Nothing on this page is legal advice.