71 terms
Collector’s Glossary
Short, plain-English definitions of the words graders, dealers and auction houses use — each linked to the guide that goes deeper.
Updated
💎 Diamonds
- 4 Cs
- Cut, color, clarity and carat weight — the four factors GIA uses to grade a diamond’s quality. The 4 Cs of Diamonds, Explained (So You Don’t Overpay) →
- Carat
- A unit of weight for gemstones equal to 0.2 grams. It measures weight, not size. Carat vs Size: Why a 0.90ct Looks Like a 1.00ct →
- Cut grade
- A rating of how well a round brilliant diamond’s proportions, symmetry and polish return light, from Excellent to Poor on the GIA scale. Diamond Cut Grades Explained: The C That Makes It Sparkle →
- Color grade
- How free a white diamond is from yellow or brown tint, on GIA’s scale from D (colorless) to Z. Diamond Color Grades Explained: The D-to-Z Scale →
- Clarity grade
- The size, number and visibility of a diamond’s inclusions and blemishes under 10× magnification, from Flawless to I3. Diamond Clarity Explained: From Flawless to Included →
- Eye-clean
- A diamond with no inclusions visible to the unaided eye from normal viewing distance. It is a trade description, not a lab grade. Diamond Clarity Explained: From Flawless to Included →
- Inclusion
- A feature inside a diamond, such as a crystal, feather or cloud, formed during growth or by stress. Diamond Clarity Explained: From Flawless to Included →
- Fluorescence
- A visible glow, usually blue, that some diamonds emit under ultraviolet light, graded None to Very Strong. Diamond Fluorescence: Does It Help or Hurt the Value? →
- Lab-grown diamond
- A diamond made in a laboratory by HPHT or CVD, with the same chemistry and physical properties as a mined diamond. Lab-Grown vs Natural Diamonds: Which Should You Actually Buy? →
- Moissanite
- Silicon carbide, a diamond simulant that is slightly softer than diamond and shows stronger rainbow fire. Moissanite vs Diamond: How to Tell the Difference →
- Diamond simulant
- A different material that imitates diamond, such as cubic zirconia, moissanite or glass. Not the same as a lab-grown diamond. How to Tell If a Diamond Is Real: Tests You Can Do at Home →
- HPHT
- High pressure, high temperature: a process used both to grow diamonds and to change the color of existing ones. Treated Diamonds: Laser Drilling, Fracture Filling & HPHT →
- Fracture filling
- A clarity treatment that fills surface-reaching cracks with a glass-like material, identifiable by a flash of color when tilted. Treated Diamonds: Laser Drilling, Fracture Filling & HPHT →
- Grading report
- An independent lab’s document describing a diamond’s measurements and grades. It is not an appraisal of value. How to Read a Diamond Certificate (GIA Report Decoded) →
- Kimberley Process
- An international certification scheme, in force since 2003, meant to stop rough diamonds from financing rebel movements. Conflict-Free Diamonds: What “Ethically Sourced” Really Means →
- Old European cut
- A hand-cut round diamond style from about 1890 to the 1930s with a small table, tall crown and visible culet. Antique Diamond Cuts Explained: Old Mine, Old European & Rose →
💍 Rings & jewelry
- Karat
- The purity of gold in parts per 24: 24K is pure, 18K is 75% gold, 14K is 58.5% and 10K is 41.7%. Ring Metals Compared: 14K, 18K, White Gold, Platinum →
- Fineness mark
- A three-digit stamp giving metal purity in parts per thousand, such as 585 for 14K gold, 925 for sterling silver or 950 for platinum. How to Identify a Ring: Hallmarks, Metals & Maker’s Marks →
- Hallmark
- An official set of marks applied by an independent assay office after testing a precious-metal item’s purity. How to Identify a Ring: Hallmarks, Metals & Maker’s Marks →
- Rhodium plating
- A thin coating of rhodium that gives white gold its bright white color; it wears and needs periodic replating. Ring Metals Compared: 14K, 18K, White Gold, Platinum →
- Melt value
- The value of a piece’s precious metal alone: weight × purity × current metal price. What Is My Ring Worth? The Four Numbers Nobody Explains →
- Prong setting
- A setting that holds a stone with metal claws, typically four or six, exposing most of the stone to light. Diamond Ring Settings Explained: Prong, Bezel, Halo & More →
- Bezel setting
- A setting that surrounds a stone’s girdle with a rim of metal, offering the most protection. Diamond Ring Settings Explained: Prong, Bezel, Halo & More →
- Halo
- A ring of small stones surrounding a center stone to make it look larger. Diamond Ring Settings Explained: Prong, Bezel, Halo & More →
- Eternity band
- A ring set with stones around all or most of its circumference; full eternity bands generally cannot be resized. How to Find Your Ring Size at Home Without Guessing →
🎨 Art & paintings
- Provenance
- The documented ownership history of an artwork, ideally traceable back to the artist. Art Provenance: Why a Painting’s History Drives Its Value →
- Attribution
- The assignment of a work to an artist or workshop. Auction wording such as “attributed to” or “circle of” signals how certain it is. “Attributed To”, “Studio Of”, “After”: Auction Wording Decoded →
- Catalogue raisonné
- A comprehensive, scholarly list of all known works by an artist; inclusion is strong evidence of authenticity. “Attributed To”, “Studio Of”, “After”: Auction Wording Decoded →
- Craquelure
- The network of fine cracks that forms in paint and varnish as a painting ages. Reading a Painting’s Condition: Craquelure, Overpaint & UV →
- Overpaint
- Later paint that covers original paint, as opposed to retouching confined to areas of loss. Reading a Painting’s Condition: Craquelure, Overpaint & UV →
- Relining
- Attaching a new canvas to the back of an old one to strengthen it. Reading a Painting’s Condition: Craquelure, Overpaint & UV →
- Impasto
- Paint applied thickly enough that brush or knife marks stand up from the surface. Oil, Acrylic, or Watercolor? How to Tell Paintings Apart →
- Giclée
- A high-quality inkjet print, often used for reproductions of paintings. Original Painting or Print? How to Tell the Difference →
- Artist’s proof (A/P)
- An impression of a print kept outside the numbered edition, traditionally for the artist. Limited Edition Prints Explained: What 12/150 Really Means →
- Edition number
- The fraction written on a print, such as 12/150: impression 12 of an edition of 150. Limited Edition Prints Explained: What 12/150 Really Means →
- Reserve
- The confidential minimum price below which an auction lot will not be sold. How Art Auctions Work: Estimates, Reserves & the Buyer’s Premium →
- Hammer price
- The winning bid at the fall of the auctioneer’s hammer, before premiums and taxes. How Art Auctions Work: Estimates, Reserves & the Buyer’s Premium →
- Sfumato
- A painting technique of soft, gradual transitions between tones, famously used by Leonardo da Vinci. The Mona Lisa: Why the World’s Most Famous Painting Is Famous →
- Fresco
- Painting on freshly laid wet plaster so the pigment binds into the wall as it dries. The Creation of Adam: The Two Fingers That Defined an Era →
- Tronie
- A Dutch Golden Age study of a face or character type rather than a portrait of an identified person. Girl with a Pearl Earring: Vermeer’s Mysterious Masterpiece →
- Triptych
- An artwork made of three panels, usually hinged. The Garden of Earthly Delights: Bosch’s Wild Triptych →
- Ukiyo-e
- Japanese woodblock prints and paintings of the Edo period depicting landscapes, theater and everyday life. The Great Wave off Kanagawa: The Print That Conquered the World →
⌚ Watches
- Movement
- The internal mechanism that powers a watch — quartz, manual-wind mechanical or automatic. Watch Movements Explained: Automatic, Quartz, Mechanical →
- Automatic
- A mechanical movement wound by a rotor that swings as the wearer moves. Watch Movements Explained: Automatic, Quartz, Mechanical →
- Chronometer
- A watch whose movement is certified to precise accuracy limits, such as COSC’s −4 to +6 seconds per day. Chronograph vs Chronometer: What the Words Really Mean →
- Chronograph
- A watch with a built-in stopwatch function, controlled by pushers. Chronograph vs Chronometer: What the Words Really Mean →
- Complication
- Any function beyond hours, minutes and seconds, such as a date, chronograph or moon phase. What Makes a Watch Valuable? A Collector’s Guide →
- Power reserve
- How long a fully wound mechanical watch runs before stopping. Watch Movements Explained: Automatic, Quartz, Mechanical →
- Cyclops
- A magnifying lens on the crystal above the date window, used by Rolex at about 2.5× magnification. How to Spot a Fake Rolex: The Tells That Still Work →
- Rehaut
- The inner ring between dial and crystal, engraved with the serial number on modern Rolex watches. How to Spot a Fake Rolex: The Tells That Still Work →
- Water resistance
- A rating from a static pressure test, expressed in metres or bar; it is not a safe diving depth. What 30m, 100m and 200m Water Resistance Actually Mean →
- Magnetization
- Magnetism in a mechanical movement’s hairspring, often causing a watch to gain minutes a day; fixed with a demagnetizer. Why Your Watch Runs Fast (and What Accuracy Is Normal) →
- Full set
- A pre-owned watch sold with its original box, papers and accessories, which usually adds value. What Makes a Watch Valuable? A Collector’s Guide →
👜 Designer bags
- Date code
- A stamp of letters and digits inside older Louis Vuitton bags recording the factory and production date; not unique to one bag. Open the tool →
- Serial number
- An identifier intended to be unique to one bag, such as Chanel’s sticker and matching card used until about 2021. Designer Bag Date Codes & Serials, Explained →
- Heat stamp
- The brand name and country of manufacture pressed into leather with a heated die. How to Spot a Fake Louis Vuitton Bag →
- Vachetta
- Untreated cowhide leather used for Louis Vuitton trims, which darkens to a honey patina over time. How to Spot a Fake Louis Vuitton Bag →
- Dust bag
- A breathable fabric bag supplied to store a handbag away from dust and light. How to Store a Designer Bag So It Keeps Its Value →
- Condition rank
- A resale grade — such as N, S, A, AB, B, C — describing a used bag’s condition; no universal standard exists. Designer Bag Condition Grades Decoded (and What They Cost You) →
- Hardware
- The metal parts of a bag: clasps, zips, feet, rings and chains, a frequent authentication point. Is My Designer Bag Authentic? The 7-Point Checklist →
🪙 Coins
- Sheldon scale
- The 1–70 numeric coin grading scale, from Poor (1) to perfect Mint State (70). Coin Grading Explained: The 1–70 Sheldon Scale, Decoded →
- Mint State (MS)
- A coin grade from 60 to 70 for uncirculated coins with no wear. Coin Grading Explained: The 1–70 Sheldon Scale, Decoded →
- Proof
- A coin specially struck for collectors, usually with mirror-like fields; graded with a PR or PF prefix. Coin Grading Explained: The 1–70 Sheldon Scale, Decoded →
- Mint mark
- A small letter or symbol showing which mint struck a coin, such as D for Denver or S for San Francisco. Is My Coin Valuable? How to Tell in Five Minutes →
- Mintage
- The number of coins struck of a given date and mint; a key driver of rarity. Is My Coin Valuable? How to Tell in Five Minutes →
- Doubled die
- A minting error in which lettering or design elements appear doubled because the die received the design from the hub more than once, slightly out of alignment. Is My Coin Valuable? How to Tell in Five Minutes →
- Legend
- The lettering around a coin’s design, often naming the issuing country or ruler. How to Identify an Old Coin: Six Clues on Every Coin →
- Obverse and reverse
- The front (usually the portrait or main device) and back of a coin. How to Identify an Old Coin: Six Clues on Every Coin →
- Slab
- A sealed plastic holder from a grading service such as PCGS or NGC containing an authenticated, graded coin. Coin Grading Explained: The 1–70 Sheldon Scale, Decoded →
- Details grade
- A grading-service label for an authentic coin with a problem such as cleaning or damage, given instead of a numeric grade. Coin Grading Explained: The 1–70 Sheldon Scale, Decoded →