Crystal identifier
Crystal identifier: what is your crystal, and is it real?
Crystal identifier from one photo: the likely crystal and its look-alikes, a value range from recent sales, signs of dye, heat or glass, and whether to keep, sell or have it tested.
The result
What the crystal identifier report shows
One crystal per photo, read in this order: what it is, how sure the match is, whether it is natural, and what it is worth.
The most likely mineral or variety, the trade name it may be sold under, and the look-alikes it was checked against, with a confidence for each.
An authenticity read: signs of dye, heat treatment, coating or glass that the photo shows, and how confident the analysis is.
An estimated range from recent sales of similar specimens, based on type, size, quality, clarity and color.
What kind of piece it is, in plain words.
- Good for beginners
- Display-grade
- Worth an expert look
Where to sell, how to store and display it, and when a gemologist's test or a jeweler's appraisal is worth the cost.
Method
How the crystal identifier works
- 01
Take a clear photo
One photo in daylight, no flash, on a plain neutral background, close enough that the crystal faces or the bands are sharp.
- 02
It identifies the crystal
From color, luster, crystal habit and banding, the identifier names the most likely crystal and the look-alikes to rule out.
- 03
It checks for dye, heat and glass
Colors that do not form in nature, heated quartz sold as citrine, coatings and signs of glass.
- 04
It estimates the value
A range from recent sales of similar specimens, raw, tumbled or polished, with the reason it is common or sought-after.
- 05
You decide what to do
Keep it, sell it or have it tested: the report says which, where to sell it and when a gemologist's test is worth it.
Reference
Raw agate identification: clues on the outside
Agate is a banded variety of chalcedony, and most agates form as nodules in volcanic rock. On a raw agate, such as a Lake Superior agate, the colored bands are usually not well exposed, so collectors look for other clues.
- A peeled texture
Where the agate broke along its band planes, the rock can look as if the bands were partly peeled off, like a banana skin.
- Translucence
Chalcedony lets light through and gives a glow; sunny days are best to see it.
- A glossy, waxy look
Above all on a chipped or broken surface.
- A pitted surface
Pits left on the outside by knobs of softer mineral that lined the cavity before the agate formed.
- Iron-oxide staining
Found on nearly all Lake Superior agates to some degree, most often rust-red and yellow.
Source: Minnesota DNR (Lake Superior agate); Wikipedia (Agate), as of
Reference
How the crystal identifier reads a crystal
Color is the first thing you see, and often unreliable on its own. The identifier weighs it with the properties a mineral book uses.
- Color
A primary identifier for quartz with visible crystals, such as amethyst and citrine, and a secondary one for chalcedony and agate.
- Luster
The way light meets the surface: glassy (vitreous), waxy, silky, greasy, metallic or earthy.
- Crystal habit
The outer shape of a crystal or a group of crystals, which reflects the order of its atoms. Most natural crystals do not show an ideal habit.
- Hardness
Scratch resistance on the Mohs scale from 1 to 10: quartz is 7, calcite 3, diamond 10. A photo cannot show it: it is the check to make in hand.
- Banding
Alternating bands of colored chalcedony mark an agate; most are banded in rings, some in straight parallel lines.
Source: Wikipedia (Quartz; Lustre (mineralogy); Crystal habit; Mohs scale; Agate), as of
Reference
Amethyst value, quartz value and crystal value: what moves the price
Quartz is the second most common mineral in the Earth's lithosphere, and amethyst, citrine and rock crystal are all quartz. What makes one specimen worth more than another is what the valuation reads.
- Color, for amethyst
The biggest factor in amethyst's value is its color. Carat weight counts less than for most gems, because amethyst is found in large pieces.
- Amethyst used to be a cardinal gem
It was counted among the most valuable gems until large deposits were found, in Brazil among other places; today it is a semi-precious stone.
- Natural or heated, for citrine
Natural citrine is rare. Most citrine on the market is amethyst or smoky quartz that was heated.
- Treated or coated quartz
Clear quartz can be heated or irradiated to give it a color, and quartz may be coated with metal vapors for a sheen. Treatment can affect its value.
- Fading
Amethyst can fade in tone if overexposed to light.
Source: Wikipedia (Amethyst; Quartz; Citrine (quartz); Gemstone), as of
Reference
Real crystal or fake? Dye, heat and glass checks
These are the signs the crystal identifier looks for in the photo. Each is a reason to look closer, not a verdict.
| What you see | What it can mean |
|---|---|
| Electric blue or bright pink in a geode | Dye: colors like these do not form in nature |
| Agate with unusually strong color | Many duller agates sold commercially are treated to enhance their color |
| Yellow or orange quartz sold as citrine | Usually heated amethyst or smoky quartz |
| Clear green quartz sold as prasiolite or green amethyst | Nearly always heated amethyst or irradiated quartz; natural prasiolite is exceedingly rare |
| A rainbow or metallic sheen on quartz | A coating of metal vapor |
- What you see
- Electric blue or bright pink in a geode
- Dye: colors like these do not form in nature
- What you see
- Agate with unusually strong color
- Many duller agates sold commercially are treated to enhance their color
- What you see
- Yellow or orange quartz sold as citrine
- Usually heated amethyst or smoky quartz
- What you see
- Clear green quartz sold as prasiolite or green amethyst
- Nearly always heated amethyst or irradiated quartz; natural prasiolite is exceedingly rare
- What you see
- A rainbow or metallic sheen on quartz
- A coating of metal vapor
Source: Wikipedia (Geode; Agate; Quartz; Citrine (quartz); Prasiolite), as of
Photos
How to photograph a crystal for identification
Color is what a dye check reads, so light and background matter most. You need no special camera: a phone scan in daylight gives the best results.
- Daylight, no flashBy a window, out of direct sun. Flash and colored lights change the color the identifier reads.
- A neutral backgroundWhite or grey paper. A colored cloth tints the crystal.
- One sharp photoClose enough that the crystal faces or the bands fill most of the frame, still in focus.
- Show a chipped edge if there is oneTurn the piece so a chipped or broken spot is in the photo: that is where agate shows its waxy luster.
- Something for sizeA coin or a ruler beside the piece shows how big it is, which the value range needs.
- Keep the tagKeep the shop tag or the listing: the seller's name for it matters when you compare it with the report.
Scope
What the crystal identifier can and cannot tell
A photo can show
- The likely crystal and the look-alikes to rule out
- The trade names it may be sold under
- Signs of dye, heat treatment, coating or glass that show in a photo
- A value range for raw, tumbled or polished pieces
- Whether it looks common or sought-after
Only an expert with it in hand can tell
- Prove a crystal is natural or untreated: a gem lab can test for it
- Find a treatment that leaves no visible trace
- Say where it was mined
- Confirm any healing or metaphysical property
A crystal name is the start. The identifier adds real or treated, a value range and what to do next, and shows its confidence so you know when to check in person.
Next
After the crystal identifier
The collecting verdict points to one of these.
- 01
Ask the seller in writing
Before you buy, ask whether the piece is dyed, heated or coated, and what it was sold as.
- 02
Keep amethyst out of the sun
Amethyst can fade in strong light: store and display it away from a sunny window.
- 03
Sell with the facts
Say what it is, its size and any treatment you know of, and price it against recent sales of similar specimens, not asking prices.
- 04
Have a valuable specimen tested
A gemologist or a gem lab can identify the material and the treatments that a photo cannot settle.
A crystal identifier app in your browser, free to try
No download from an app store. Trying the form is free: your first checks need no card and no account, and there is no trial that turns into a subscription. It runs online, on a phone or a computer.
Limits
What a crystal identifier cannot promise
The crystal identifier flags what a photo can show; it does not prove what a crystal is: a gem lab can test for it. Values are estimates from recent sales, not an offer or an appraisal. Nothing here is investment advice. We do not buy or sell crystals.
FAQ
Crystal identifier questions
What does the outside of an agate look like?
Not like the polished slices in shops: on a raw agate, such as a Lake Superior agate, the bands are usually not well exposed. Look for a pitted surface, a peeled texture where it broke along its bands, a waxy look on a chipped spot, and a glow when light passes through.
What does an agate look like inside?
Alternating bands of colored chalcedony, most often in rings that follow the shape of the cavity, sometimes in straight lines. The center may hold quartz crystals, or a hollow lined with them.
How to identify agate from other stones?
Look for bands, translucence and a waxy luster. Some banded stones are not agates, such as banded chert, and some stones called agate have no bands, such as moss agate. The identifier names the look-alikes it ruled out.
Is there a free crystal identifier app that actually works?
This one runs in your browser with no app to download, and your first checks are free: no card, no account. It shows its confidence and the look-alikes, so you can see how sure the identification is.
Why do different apps give different crystal names for the same photo?
Color misleads: the same mineral comes in many colors, and different minerals share one. The identifier weighs color with luster, habit and banding, and shows the look-alikes instead of one name.
Can it tell real crystals from synthetic or fake ones?
It flags the signs a photo can show: dye, heat treatment, coatings and glass. Synthetic amethyst has the same properties as natural amethyst and needs advanced testing, so the report says when only a lab can settle it.
How much is my amethyst worth?
Mostly its color: amethyst is found in large pieces, so size counts less than for most gems. The value range compares your piece with recent sales of similar ones.
Is my citrine real?
It is probably quartz either way, but natural citrine is rare: most citrine sold is heated amethyst or smoky quartz. The identifier says which way the photo points.
Is my geode dyed?
Electric blue or bright pink inside a geode is the usual sign: those colors do not form in nature. Natural geodes are lined with quartz, amethyst, agate, calcite or other minerals. To tell whether a closed rock is a geode at all, see what type of rock is this?.
Is this a professional appraisal or just an estimate?
An estimate from recent sales, to help you decide; the report answers what a photo can. For insurance or a high-value sale, a gemologist or a jeweler appraises the piece in hand.
Can I sell my crystal based on this estimate?
You can use it to set a starting price and to describe the piece honestly. A buyer decides what to pay, and treatments should be disclosed.
Checking what you were sold?
Photograph it in daylight, keep its shop tag to compare, and see what it most likely is and whether it looks dyed or heated.