Chrysoprase is the best green in the quartz family, and it earns that title honestly: an apple-green, slightly translucent chalcedony with a colour no dye reproduces convincingly. It is also the stone most often substituted, because "green chalcedony" covers a lot of material that is not chrysoprase at all.
The distinguishing feature is the colour source. Chrysoprase is green because of nickel in the crystal lattice. Dyed agate is green because someone put dye in it. Those are different products and they behave differently over time.
What chrysoprase is, in mineral terms
Microcrystalline quartz — chalcedony — coloured by nickel. Hardness 6.5 to 7 on the Mohs scale, no cleavage, tough and fine-grained. This is one of the more forgiving bracelet stones: it does not cleave, it takes a good polish, and it tolerates ordinary wear.
Quality is graded almost entirely on colour and translucency. Fine chrysoprase is an even, saturated apple green with a slight glow when backlit. Lower grades are pale, patchy, or carry brown and white inclusions of the host rock.
Where it comes from
Australia, particularly Queensland, has supplied the classic material for over a century. Tanzania, Brazil, Russia and Madagascar also produce it. Australian chrysoprase is often the most consistent in colour; African material can be brighter but more variable.
Origin is not a guarantee of quality — sorting is. A well-sorted strand of Tanzanian beads beats a badly sorted Australian one every time, and the price should follow the beads, not the postcode.
How to tell it from dyed agate and imitation
Colour distribution. Natural chrysoprase is usually even, with subtle variation. Dyed green agate often shows dye concentrated in cracks and a faintly bluish or artificial cast. If the green looks slightly "chemical" next to skin, trust that instinct.
Translucency. Good chrysoprase glows at the edges when backlit. Dyed opaque agate does not, and green aventurine — a legitimate but different stone — sparkles instead of glowing.
Nickel test. Not something you can do at home, but worth knowing: chrysoprase colour comes from nickel, and a lab can confirm it in minutes. Reputable sellers who specialise in the material will have done this.
Watch for "green onyx". In the bead trade this almost always means dyed or heat-treated agate, not onyx and not chrysoprase. The name is a marketing convention, not a mineral description.
Heat, light, and why chrysoprase fades
Chrysoprase is sensitive to heat. Prolonged exposure to strong sunlight or high temperatures can shift the green toward pale grey-green, and the change is not reversible. This is a nickel colour centre behaving the way nickel colour centres do.
Practically: do not leave a chrysoprase bracelet on a car dashboard, and store it in a box rather than on an open shelf. Normal wearing is fine; it is sustained exposure that causes the problem.
What to look for when you buy
Saturation. Deep apple green with no grey undertone is the target. Pale mint-coloured material is common and inexpensive; the price difference between grades is steep and visible.
Evenness. A bracelet with matched colour across every bead took more rough and more sorting. Patchy strands are cheaper for a reason.
Surface. Chrysoprase polishes to a smooth, almost waxy lustre. A glassy, wet-looking surface on cheap green beads usually means dyed agate or glass.
Inclusions. Small white or brown specks are natural and acceptable in mid-grade material. Heavy brown veining drops the grade sharply. Our size guide covers fit and bead counts.
Care and wear
Warm water, mild soap, soft cloth. Chrysoprase is tough enough for ultrasonic cleaning but we would not bother — it does not need it, and heat is its weakness, not dirt.
Keep it away from prolonged sun and from hot water. Store separately from harder stones such as sapphire or diamond. Full method in the crystal care guide.
What the meaning claims can and cannot support
Chrysoprase is traditionally linked to the heart and to emotional steadiness, and Alexander the Great is said to have worn it. That is a historical anecdote, not evidence, and there is no clinical support for any effect on a wearer.
What is defensible is the aesthetic case: it is the most convincing natural green available for everyday jewellery at a moderate price, it does not look like glass, and it improves an outfit in a way that most stones do not. That is a good enough reason to own one.
Frequently asked questions
Is chrysoprase a quartz? Yes, in the sense that it is chalcedony — microcrystalline quartz. It is not a single crystal and has no cleavage.
What gives chrysoprase its colour? Nickel in the crystal lattice. Dyed green agate is coloured by dye, which is why the two behave differently over years.
Is green onyx the same as chrysoprase? No. "Green onyx" in bead listings is usually dyed or heat-treated agate.
Does chrysoprase fade? Yes, with prolonged heat or strong sunlight. The change is not reversible, so store it away from direct light.
What is its hardness? 6.5 to 7 on the Mohs scale, with no cleavage, which makes it one of the tougher bracelet stones.
See the current green bracelets, or compare it with green aventurine and agate.