Crystal Treatment Chart: Heat, Irradiation & Dye by Stone

Which crystal-bracelet stones are commonly heated, irradiated or dyed, visible clues and their limits, and why honest disclosure matters. A by-stone reference chart.

Compare materials in the Care & Durability Checker

Published

By · 4 MIN

In this field note
In one paragraphCrystal colour can be natural or altered by heat, irradiation, dye or coating. Disclosure states what was done. This chart describes treatments to check by material and the clues that may call for testing. Colour, zoning or bubbles alone cannot certify identity or treatment.

A treatment declaration helps explain what happened to a stone before it became jewellery. Heating, irradiation, dyeing and coating can change different properties, and their use varies by material. This chart introduces those treatments and the observations that may prompt a closer check. For a finished piece, read the declaration attached to its material and lot.

Crystal treatment chart, heat, irradiation and dye by stone. BE.
Common treatments by stone, and the tells that reveal them. Image: BE.
BE.
Clear Quartz Cube Strand Bracelet
SHOP NOW

Treatment chart by stone

This chart describes treatment possibilities for different materials. The treatment status of a BE. selection is recorded for its lot in the Stone Origin Record.

Stone Treatment to read about What to observe
Citrine Heating amethyst can produce yellow quartz. Read the heating status recorded for the material.
Prasiolite (“green amethyst”) Green quartz may be produced by heating certain amethyst. Describe the colour, then read the treatment statement for the material.
Smoky Quartz Artificial irradiation can alter quartz colour. Read the recorded status; see the Smoky Quartz material guide.
Amethyst Read whether heating, irradiation or dye is recorded. Observe zoning and any colour concentrated along fractures.
“Strawberry / cherry quartz” Read the material identity and treatment statement. Observe colour distribution and any bubble-like features.
Clear Quartz Surface coatings are one possible alteration. Note where any iridescent effect appears as the piece turns.
Rutilated Quartz Check the treatment record for the specific material and lot. Needle inclusions do not establish whether colour treatment was used.
Hematoid Quartz Read the declaration for the material and lot. Observe the location of coloured inclusions and any colour concentrated along fractures.
Rose Quartz Read the status recorded for the material and lot. Describe the pink hue, translucency and distribution of colour.
Aquamarine Often heated (greenish to blue) Common, stable, should be disclosed.
Moonstone, Garnet, Obsidian, Kyanite Read the treatment line for the specific material. Describe colour and optical effects separately from treatment status.

The four treatments, explained

  • Heat. Can change colour in some materials, including certain amethysts and aquamarines. The treatment should be disclosed; colour stability and care depend on the material.
  • Irradiation. Can alter colour. The treatment process and any required radiation measurements are separate from the colour a buyer sees.
  • Dye. Adds colour to gem material. Observe the distribution of colour around fractures and drill holes, then read the treatment statement.
  • Coating. An applied surface layer can change a gem’s appearance. Read the stated treatment and care instructions.

Observations to make before reading the record

  • Observe zoning. Note the position and shape of colour bands under consistent light.
  • Inspect cracks and holes. Note any concentration of colour around them.
  • Compare colour. Use the same light and background when looking across several beads.
  • Observe sheen. Turn the piece and note where the effect appears. Rainbow colours can have more than one cause.
  • Read the treatment statement. It should name any declared treatment and the material or lot it applies to.
BE.
Hematoid Quartz Strand Bracelet
SHOP NOW

How BE. handles treatment

BE.
Multicolor Rutilated Quartz Bracelet
SHOP NOW

BE. records treatment status by lot in the Stone Origin Record. The Bolivian Amethyst Strand Bracelet is an untreated Signature selection from Bolivia, lot 2026.01. Its purple appearance can be considered alongside that record and the finished size when choosing a strand.

Related reading

Frequently asked questions

Q1.Are most crystals treated?

Treatment varies by material and lot. Some yellow quartz is heat-treated amethyst; a natural quartz identity does not itself establish an untreated status. Read the specific treatment record. The same distinction applies to hematoid quartz.

Q2.Is heat treatment bad?

Heat treatment should be disclosed. It can alter colour, and stability and care depend on the material. For a BE. piece, read the status recorded for its specific material and lot.

Q3.How can I tell if a crystal is dyed?

Dye identification uses gemmological examination alongside the treatment information supplied for the material. At home, note the distribution of colour and keep that observation with the product record.

Q4.Is irradiated smoky quartz safe?

Colour alone cannot establish the radiation status of an irradiated object. The relevant evidence is documentation and measurement for the treatment process used. GIA’s review of gemstone irradiation and radioactivity explains why colour treatment and radioactivity require separate consideration.

Q5.What does untreated mean?

Untreated records the absence of treatments such as heating, artificial irradiation, dyeing, coating and filling. Cutting, drilling and polishing shape a stone into a bead. Read the treatment declaration for the specific lot alongside the material identity.

Q6.Why should treatment be disclosed?

Treatment can affect appearance, value and care. A clear declaration lets you include that information when choosing a piece.

References