LumaLark gem and bead materials wiki

What this wiki can do for you

Who it is for

Anyone who wants to know what their beads, bracelet or gemstone is really made of: shoppers who want to understand a seller's description before buying, sellers who want their listing names and treatment notes to be accurate, and people in the trade comparing how different organisations name the same stone.

Where the information comes from

Names, definitions and what a seller has to mention all come from standards and handbooks published by gem organisations such as China's GB/T 16552, GIA and CIBJO, and every point says which one. Those documents are kept on file, and an editor checks each statement against them by hand before it is published; anything not yet checked is marked as pending. When the organisations disagree, every version is shown side by side and this wiki's own call is labelled as ours.

What it cannot do

It cannot tell you whether the piece in your hand is natural, where it came from or whether it has been treated; for that you need a report from a gem testing laboratory. It gives no prices or valuations and does not rank sellers. Intention themes are this site's own reading of what a piece can mean to the wearer and are kept apart from material facts.

How evidence is weighed and checked: Methodology. Spotted a mistake, or wondering how the wiki stays neutral: Editorial policy. Who the editors are and how to reach them: About this wiki.

Look up a material

Know the name? Find it A to Z. Only know roughly what it is? Browse by family or group. Each entry covers what it is called, whether it suits everyday wear and how it is commonly treated.

• Material entries A–Z

  All 433 materials in alphabetical order; you can also find one by a nickname or the trade name a seller uses.

• How to read material facts

  Why can a very hard stone still chip or break? Can you tell a stone by its colour alone? Read this before the entries.

• Material families

  30 groups that put related materials side by side, such as quartz and chalcedony, jade, or pearls and shell.

• Classification axes

  Browse materials another way, by 5 kinds of grouping (Origin class, Material domain, Identity level, Mineral chemical class, Construction or treatment status), with a page for each group.

• Recorded localities

  Where each material comes from according to authoritative sources, on a land-only sketch map with the localities listed by continent.

• Pearl-producing molluscs

  Which shellfish pearls come from: the scientific and common names of pearl oysters and mussels, where they live and what they produce, with local names by region.

Treatments, testing & care

Has a stone been heated, dyed or filled, and does the seller have to say so? What do the words on a lab report mean? How should you clean and store it?

• Treatments & disclosure

  Heating, dyeing, filling, irradiation and more: 11 common treatments, what each one does, and how a seller should describe it.

• GB/T 16552: optimization vs treatment

  China's national standard calls some processes optimization and others treatment, and treatment must be named on the label. How to check which is which, for example why dyed chalcedony and irradiated rock crystal count as optimization.

• Laboratory testing & report wording

  Can't make sense of a lab report? Which tests 120 gem materials need, what each test checks, and what the report wording means.

• General gem care

  Care that suits every gemstone: washing in warm soapy water, storing pieces apart, when an ultrasonic cleaner is risky, and the extra care some stones need.

Getting the name right

The same stone can go by different names, and some trade names mislead buyers. Here is what to call a material and which names to avoid.

• Naming authorities

  Who GIA, CIBJO, the US FTC, China's GB/T standard, Japan's GSJ and the UK's Gem-A are, and what each one covers.

• Where authorities disagree

  50 materials that different organisations name differently, with each name side by side.

• Naming governance

  When the organisations disagree, which name this wiki uses and why.

• Misleading & prohibited trade names

  Vague labels such as semi-precious, and trade names that mislead buyers: why they should not be used and what to say instead.

• Supplementary name index

  Names you may come across that have no entry of their own here: where each comes from and a one-line note on what it refers to.

• CIBJO term definitions

  What everyday trade terms mean according to CIBJO, the World Jewellery Confederation: weights, optical effects, cutting, names, care and trade documents.

• Reference glossary

  Every specialist term used on this site in one table, each with a one-line definition.

Meanings & culture

The meanings and cultural background people attach to beads. Intention themes are this site's own interpretation and cultural records cite their sources; both are kept apart from the material facts above.

• Intention themes

  16 themes such as protection, love or calm, each with a few questions to help you decide what you want, and the materials linked to it on record.

• Cultural records

  7 pages on the symbols and customs behind beads, such as the evil eye, the hamsa, prayer beads and birthstones, each with its community, period and sources.

Can you trust it?

Where the information comes from, who looks after it, when pages changed, and how to tell us about a mistake.

• Guides

  Longer reads: can a lab really tell where a stone came from, what decides quality and price, and how gem testing grew into a science.

• Methodology

  Which documents this wiki relies on, how strong each kind of evidence is, and how every entry is checked by hand before it goes live.

• Editorial policy

  Who is responsible for what is written, how mistakes are corrected in the open, and how the wiki stays neutral towards the materials sold in the LumaLark shop.

• Revision history

  When each page last changed, newest first.

• About this wiki

  What the wiki covers, where its information comes from, who maintains it and how to get in touch.

By the numbers

Materials covered

433

Intention themes

16

Cultural records

7

Common treatments

11

Naming organisations consulted

6

Browse-by-group pages

36

Rows in the name table

437

Materials with a definition from a standard

278

Materials that need a note to buyers

422