Chrysoprase

Green without being jade

Chrysoprase is green chalcedony: a fine crystalline silica aggregate whose characteristic colour is associated with nickel. GIA’s studies describe colours from pale green through richer apple greens; recently examined Western Australian samples ranged from yellow-green to blue-green. Colour words describe appearance, not a separate mineral species or quality grade.

The historic sales name “Queensland jade” is misleading. Chrysoprase is not jadeite or nephrite. Nor should every green chalcedony be called chrysoprase: other colouring mechanisms and deliberately dyed material must be considered. An identification should establish the material, not merely match a photograph.

The usual hardness range for chalcedony is about 6.5–7 on the Mohs scale. This is a scratch-resistance guide, not a guarantee against chipping; fractures, inclusions and any treatments can change the practical durability of a particular object.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Brazilian chrysoprase, Summer 1990, International Colored Gemstone Association: Chalcedony

Properties and visible character

Cabochons, beads and carvings suit the material’s aggregate texture. In GIA’s 2026 study, spot refractive-index readings were 1.53–1.54 and measured specific gravity ranged from 2.59 to 2.65. Those are results for the studied suite rather than precision guarantees for every piece. The samples also contained cottony white and tiny coloured inclusions.

An attractive stone need not be entirely uniform. GIA has documented dendritic inclusions in Australian chrysoprase, with nickel-bearing green zones alongside nearly colourless areas. Compare the face-up effect, polish and translucency rather than assuming every visible variation is a defect or proof of dye.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Chrysoprase inclusions, Spring 2009

A geographically specific story

Australia is an important documented source, including Queensland and Western Australia. GIA has also reported chrysoprase from Goiás in Brazil and from the Haneti area of Tanzania. The Tanzanian material occurs in veins associated with altered serpentinite; it must be distinguished from the green common opal mined in the same region.

A 2026 GIA note examined new Western Australian production that had appeared in Bangkok markets since mid-2024. The report places it near the known Yerilla deposit but attributes the discovery account to the supplier. It is evidence of a studied parcel and reported source, not an independent forecast of future supply.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Brazilian chrysoprase, Summer 1990, GIA: Chrysoprase and Prase Opal from Haneti, Central Tanzania

Disclosure and care

Ask explicitly whether green colour is natural and whether impregnation or other treatment is present. A confident trade name is not a laboratory conclusion. When origin or untreated status materially affects a purchase, seek appropriate documentation rather than relying on saturation alone.

For routine cleaning of sound modern jewellery, favour a soft damp cloth or brief gentle washing over heat, aggressive chemicals or mechanical cleaning. Treat unknown surface coatings and fillings cautiously. Store pieces individually so harder gems cannot abrade them, and have cracked or antique pieces assessed before cleaning.

Evidence: GIA: An Introduction to Gem Treatments, GIA: Gemstone Durability, Design to Display

Why more than one test matters

The Haneti study offers a useful comparison: similarly green chrysoprase and prase opal were separated by refractive index and specific gravity. The reported approximate values were 1.55 and 2.60 for chrysoprase, compared with 1.45 and 2.11 for the opal. Similar colour can therefore conceal a substantial difference in material identity.

A refractometer measures optical behaviour; specific gravity compares density with water. Neither is a colour grade. The Western Australian report also combined microscopy with spectroscopy and elemental analysis. Agreement among complementary observations is stronger evidence than finding one number or one photograph that seems to fit a preferred name.

Evidence: GIA: Chrysoprase and Prase Opal from Haneti, Central Tanzania, GIA: New Chrysoprase Production from Western Australia

Two green cabochons, two different claims

Imagine a listing that describes one cabochon as Queensland jade and another as untreated chrysoprase from Australia. The first phrase does not supply an accepted jade identification. The second makes three claims: material, treatment status and geographic origin. Ask what supports each claim rather than accepting the more detailed sentence as automatically more reliable.

For visual comparison, place the stones under the same neutral light and note their thickness. Describe green hue, the amount of light transmitted, any pale zones and the quality of the polish. These observations help compare design and appearance. They cannot independently prove nickel as the colour cause, exclude dye or locate the deposit.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Brazilian chrysoprase, Summer 1990, GIA: An Introduction to Gem Treatments, GIA: Chrysoprase and Prase Opal from Haneti, Central Tanzania

From aggregate to absorption

An aggregate contains many small crystals rather than one continuous crystal. A chromophore is a constituent responsible for colour; nickel is central to chrysoprase’s green. Absorption means that selected wavelengths of light are removed more strongly than others. A dendrite is a branching mineral growth, not automatically a plant fossil. A spot refractive-index reading is an approximate measurement suited to a curved polished surface.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Chrysoprase inclusions, Spring 2009

Self-check: read the research claim carefully

Does green colour alone separate chrysoprase from prase opal? No. Does a reported deposit near Yerilla establish the source of every Australian-looking cabochon? No. Would the presence of natural inclusions automatically exclude later treatment? No. Keep the specimen actually studied, the supplier’s reported locality and your own unknown object distinct.

Evidence: GIA: New Chrysoprase Production from Western Australia, GIA: Chrysoprase and Prase Opal from Haneti, Central Tanzania, GIA: An Introduction to Gem Treatments

Places in the story

These places describe documented sources or historical settings. They do not establish the origin of an individual object.