Amethyst: Natural, Dyed or Heated, and How to Tell
Amethyst is the most counterfeited stone in the decorative crystal trade, not because fakes are sophisticated but because buyers expect the wrong thing. People expect flat, even purple. Natural amethyst is almost never flat, even purple – so the pieces that match the expectation are usually the treated ones.
This page covers what natural amethyst looks like, the three things sellers do to it, and the words on listings that actually mean something.
What natural amethyst looks like
Amethyst is quartz coloured by trace iron and natural irradiation. Three things follow from that:
- The colour is banded, not uniform. It is strongest at the crystal tips and fades toward the base, because the colour formed as the crystal grew. A cross-section shows stripes.
- The base is grey-white rock. On a cluster, that pale layer underneath is the geode wall the crystals grew on. It is not a mount someone glued on, and its presence is a good sign.
- Clarity varies within one piece. Veils, internal fractures and cloudy zones are normal. A piece that is uniformly glass-clear and uniformly purple is worth a second look.
The three treatments
1. Dyeing
Cheap quartz or agate soaked in purple dye. The tells: colour pooling darker in cracks and pits, an unnaturally even tone across the whole piece, and sometimes a faint colour transfer onto a damp white cloth. Dyed pieces are often sold as "amethyst agate slice" or simply "purple crystal".
2. Heat treatment
Heating amethyst turns it yellow-orange. Most commercial citrine is heat-treated amethyst, and you can usually recognise it by a burnt-orange cast concentrated near the base, with white at the very bottom. This is not a scam when disclosed – it is standard trade practice – but it is relevant if you are buying "citrine" expecting natural yellow quartz, which is scarce and expensive.
3. Irradiation
Pale amethyst can be darkened by irradiation. It is genuinely amethyst afterwards and is effectively undetectable without lab equipment. Practically speaking, this one is not worth worrying about.
Origin words that mean something
- Uruguayan – typically darker, more saturated purple, smaller crystal faces, higher price per gram.
- Brazilian – lighter to mid purple, larger crystal faces, the most common on the market and the better value.
- Zambian – deep purple, often with reddish flashes, usually sold as faceted gems rather than clusters.
Origin claims are unverifiable at this price level. Treat them as a description of appearance, not provenance.
Cluster, geode, cathedral – what the words mean
- Cluster – a piece cut from a geode wall, crystals on one face, flat sawn base. What most people mean.
- Geode – a hollow rock lined with crystals. A "half geode" is one cut open; a whole one is a closed lump.
- Cathedral – a tall, upright geode section, often half a metre or more. Expensive largely because of weight.
- Druzy – a surface of very fine crystals, like sugar. Not a size or quality claim.
- Point / tower – a machine-cut and polished shape, not a natural crystal habit. See our size guide.
What size to buy
Amethyst clusters are sold by weight, which is the honest way to do it, because a flat wide piece and a chunky narrow one of the same weight look very different.
| Weight | Roughly | Suits |
|---|---|---|
| 50–60 g | Palm-sized | A desk, a shelf edge, a bedside table |
| 80–100 g | Half a deck of cards | A shelf where it is the only object |
| 100–150 g | A deck of cards | Reads as an object in the room |
| 300 g+ | Two decks and up | A centrepiece – and freight starts to dominate the price |
Care: the one thing that actually matters
Amethyst fades in sunlight. This is real, not folklore – the same iron colour centres that make it purple are broken down by UV. A piece on a south-facing windowsill will visibly pale over months to years. Keep it out of prolonged direct sun and it will hold its colour indefinitely.
Otherwise: dust with a dry soft brush. A brief rinse is fine; prolonged soaking is pointless and can loosen crystals on a fragile cluster.
A note on claims
We make no claims that amethyst affects sleep, calm, health or anything else measurable. It is a decorative mineral. Buy it because you like looking at it.
What we sell
- Raw Amethyst Cluster – natural, undyed, cut from geode, sold in 50–60 g, 80–100 g and 100–150 g bands. We do not stock above 150 g; the freight outweighs the extra stone. No lab certificate is supplied.
- Crystal Tower Trio – includes an amethyst tower if you want it as part of a group.
- Seven Chakra Stone Set – includes a small amethyst as the third-eye stone.
Also useful: agate coasters: dyed or natural · crystal shapes explained · how to tell if a crystal is real · rose quartz vs amethyst · buying a crystal as a gift · the seven chakra stones explained · crystal gifts for Christmas, by recipient
Browse: Crystals · Crystal Sets
FAQ
How can I tell if amethyst is real?
Natural amethyst is colour-banded, strongest at the crystal tips and paler toward the base, with a grey-white rock layer underneath on a cluster. Flat, perfectly even purple throughout usually indicates dye.
Is dyed amethyst worthless?
Not worthless, just not what was claimed. The problem is the description, not the dye.
Why is my amethyst pale at the bottom?
That is normal and a sign it is natural. Colour forms as the crystal grows, so it concentrates at the tips.
Is most citrine really heated amethyst?
Yes, most commercial citrine is. Look for a burnt-orange cast near the base. Natural citrine is paler, more even and considerably more expensive.
Does amethyst fade in sunlight?
Yes. UV breaks down the colour centres. Keep it off a sunny windowsill and it holds its colour indefinitely.
What is the difference between a cluster and a geode?
A geode is the whole hollow rock lined with crystals. A cluster is a piece cut from its wall – crystals on one face, flat sawn base.
What weight should I buy?
50–60 g is palm-sized and suits a desk. 100–150 g is about the footprint of a deck of cards and reads as an object in a room. Above 300 g, shipping starts to dominate the price.