Is hiddenite the same as kunzite?
Hiddenite and kunzite are the same mineral, spodumene, LiAlSi2O6 (GIA): green against pink to violet. Hardness 6.5 to 7 and density 3.03 to 3.23 for both.
They are the same mineral but not the same variety. GIA calls kunzite the pink to violetish purple variety of spodumene, LiAlSi2O6, and names green hiddenite as another; neither name has an IMA row. Hardness 6.5 to 7 and density 3.03 to 3.23 are the same for both, so a balance cannot choose: colour, and a chromium spectrum for hiddenite in IGS’s stricter rule, do.
In short
- One species. The September 2026 IMA-CNMNC Master List has a row for spodumene, LiAlSi2O6, status A, 1962 s.p., and, on a whole-word scan of every line, none for hiddenite, kunzite or triphane. The GIA kunzite page calls kunzite the best-known variety of spodumene and names green hiddenite and yellow triphane as the others.
- Nothing physical separates them. On the Handbook of Mineralogy spodumene sheet both are hardness 6.5 to 7, density 3.03 to 3.23, biaxial (+), with good {110} cleavage. A 20.00 g piece reads 13.40 to 13.81 g in water as either; at GIA’s kunzite SG of 3.18, 13.71 g.
- The colour-and-spectrum rule. Pink to violet is kunzite. Green is hiddenite on GIA’s wording; the International Gem Society spodumene article is stricter, requiring a chromium spectrum (a double line at 6905/6860) and saying green Brazilian spodumene, which contains no Cr, is not hiddenite. Green without the lines: call it green spodumene and both sources agree.
- Documented failure 1: one crystal, two colours. The sheet prints pleochroism X = purple to green, Z = colourless, and the 2020 Gems and Gemology note describes the purple and green of a 2,950 g kunzite crystal seen in two orientations. A green look down one direction is not hiddenite.
- Documented failure 2: colour can be made. IGS says irradiation produces pink from colourless or green from pink, and that X-irradiated kunzite may turn blue-green, a colour that disappears in sunlight. A green stone’s history is not on its surface.
| Criterion | Kunzite | Hiddenite | Green spodumene without Cr | Triphane | Emerald (for contrast) | Does it choose? |
|---|---|---|---|---|---|---|
| Species and IMA row | Spodumene, LiAlSi2O6 (A, 1962 s.p.); no kunzite row | Spodumene; no hiddenite row | Spodumene | Spodumene; no triphane row | Beryl, Be3Al2(Si6O18) (G); emerald is its variety (GIA) | Only against emerald |
| Colour (source) | Light pink to violetish purple (GIA) | Green (GIA); medium dark green (IGS) | Green, blue-green (IGS) | Yellow (GIA, IGS) | Bluish green to green (GIA) | Yes, among the spodumene names |
| Chromium spectrum (IGS) | Not diagnostic | Required: double line at 6905/6860, weak lines at 6690 and 6460, broad absorption at 6200 | Absent (Brazil: no Cr, IGS) | Not stated | Not read here | Yes, on IGS’s rule; needs a spectroscope |
| Longwave UV (IGS) | Moderate to strong, pink to orange | Inert | Not stated | Not stated (yellow-green: orange to yellow) | Not read here | Supports, does not decide |
| Hardness | 6.5 to 7 (sheet); 6.5 to 7.0 (GIA) | 6.5 to 7 (sheet) | 6.5 to 7 (sheet) | 6.5 to 7 (sheet) | 7.5 to 8 (GIA) | No, among the spodumene names |
| Density or SG | 3.03 to 3.23 (sheet); 3.18 (GIA) | 3.03 to 3.23 (sheet) | 3.03 to 3.23 (sheet) | 3.03 to 3.23 (sheet) | 2.72 (GIA) | No, among the spodumene names |
| 20.00 g piece in water | 13.40 to 13.81 g; 13.71 g at GIA’s 3.18 | 13.40 to 13.81 g | 13.40 to 13.81 g | 13.40 to 13.81 g | 12.65 g at GIA’s 2.72 | Only against emerald |
| Refractive index | 1.660 to 1.676 (GIA) | 1.648 to 1.679 on the sheet for all spodumene | As hiddenite | As hiddenite | 1.577 to 1.583 (GIA) | Only against emerald |
| Wrong name for | Any green or yellow spodumene | Pink spodumene; and, on IGS’s rule, green without Cr | Nothing: always correct for green spodumene | Pink or green spodumene | Any spodumene | - |
Is hiddenite the same as kunzite? Same mineral, different variety
Hiddenite and kunzite are one mineral species, spodumene, LiAlSi2O6, and two variety names for two colour ranges. The GIA kunzite page calls kunzite the best-known variety of spodumene, with green hiddenite and yellow triphane the others, and gives kunzite’s colour as pink to violetish purple, refractive index 1.660 to 1.676, specific gravity 3.18 and hardness 6.5 to 7.0. The GIA kunzite description repeats the light pink to violetish purple definition.
What the IMA list says. A whole-word, case-insensitive scan of every line of the September 2026 list finds spodumene, LiAlSi2O6, status A, 1962 s.p., Sweden, and no line containing hiddenite, kunzite or triphane. The species is spodumene; the names are trade and collector varieties of it. The pyroxene placement of spodumene is on is spodumene a pyroxene, and the species itself, with its cleavage rule, on spodumene; neither is repeated here.
Where the names come from. The GIA kunzite history page says pink crystals from San Diego County, California, were confirmed as spodumene by George Frederick Kunz in 1902, and that Charles Baskerville named kunzite for him in 1903. IGS says hiddenite was first found in North Carolina, USA. The sheet’s Distribution field names spodumene localities in North Carolina and the Pala district, San Diego Co., among others.
How do you choose between kunzite and hiddenite? The colour-and-spectrum rule
The rule: pink to violet is kunzite; green with a chromium spectrum is hiddenite on every source read here; green without it is safest labelled green spodumene. The two sources differ on the middle case. GIA’s wording, green hiddenite, would cover any green spodumene. The International Gem Society spodumene article is narrower: it describes hiddenite as a medium dark green and lists its absorption spectrum as a chromium spectrum, a double line at 6905/6860 with weak lines at 6690 and 6460 and broad absorption at 6200. Of the localities it lists, it says material from Minas Gerais, Brazil, contains no Cr, and its green varieties are not hiddenite.
What this rule does not claim. IGS gives the chromium lines as an identification feature. This page states no colour cause for either variety; none of the pages read here measures one. Running the rule on a green stone needs a spectroscope; by eye, the honest label for an untested green spodumene is green spodumene.
Ultraviolet supports the choice but does not make it. IGS gives kunzite a moderate to strong pink to orange longwave response, weaker in shortwave, and hiddenite inert in both. The spodumene sheet records yellow, orange or pink fluorescence under LW and SW, and the 2020 Gems and Gemology note recorded weak and moderate orange zoned longwave fluorescence in the stone it examined. Lamps are on best UV lamp for mineral collecting.
Why can a kunzite crystal look green? Two documented failures
Pleochroism: one spodumene crystal can show purple in one direction and green in another. The Handbook spodumene sheet prints the pleochroism as X = purple to green, Z = colourless. Tuzlukov, Kaewchaijaroenkit and Sturman (Gems and Gemology, Summer 2020) describe a 2,950 g rough kunzite crystal from Kunar Province, Afghanistan, whose pronounced pleochroism, seen in two orientations, showed the same purple and green colours as the 3,051 ct stone cut from it. IGS adds that kunzite crystals are colourless on the long axis and pink to violet down the c axis. A green flash down one axis of a pink crystal is not hiddenite.
Treatment: colour can be changed in both directions. IGS lists irradiation as producing pink from colourless or green from pink, and says X-irradiated kunzites may change colour to blue-green, a colour that disappears in sunlight. The GIA kunzite description adds that kunzite can be irradiated and then heat-treated, and that both treated and natural colour can fade with exposure to heat and bright light. The general question is on which minerals fade in light; no test for treatment is offered here, because none is given by these sources.
What both failures mean for a label. Colour, with the spectrum IGS adds to it, is what separates the two names, and the sources above show that colour can change with viewing direction, treatment and light. The species name, spodumene, is the one that cannot be wrong.
Is hiddenite a green emerald? The lithia-emerald name
No: emerald is a different species, beryl, and the scale, the refractometer and hardness all separate it from hiddenite. The GIA emerald page calls emerald the bluish green to green variety of beryl, Be3Al2Si6O18, with refractive index 1.577 to 1.583, specific gravity 2.72 and hardness 7.5 to 8. A 20.00 g emerald reads 12.65 g in water at that SG; any spodumene reads 13.40 to 13.81 g. The misleading trade name lithia emerald for hiddenite, from the International Gem Society list of false gemstone names, and the full spodumene-against-beryl separation are on is kunzite a beryl and are not repeated here.
Why the confusion persists. Spodumene and beryl grow in the same granite pegmatites: the spodumene sheet lists beryl among its associates. Aquamarine and emerald, the blue and green beryls, are on is aquamarine a beryl.
Labelling a specimen. Spodumene (kunzite) for pink to violet; spodumene (hiddenite) for green with a chromium spectrum; spodumene for anything untested. More identification guides are in the collecting guides. Nothing on this site is offered for sale; the wanted list is the only commercial route.