About

The World Coin Database began in 2010 out of frustration with the Numismaster website, run by the publishers of the Standard Catalog of World Coins. While its content was large, the search functionality was limited, and many of the photos were of low quality. Since then, many other coins sites have been established (probably for the same reason), and eclipsed Numismaster in function and quality. However, most of these do not have the searching, identification, and learning (through links to Wikipedia) features that the World Coin Database provides (or intends to provide). As the World Coin Database has a single contributor (myself), development toward these goals has been slow. However, I enjoy both coin collecting and web development as hobbies, so this site allows me (or gives me motivation to) continue learning about both.

Structure

The World Coin Database attempts to use a very structured approach to store its data. This (hopefully) enables easy identification, logical browsing, and prevents conflicting information. The approach was to structure the data similarly to how a coin is made, starting with raw materials, then the design characteristics. Below is a diagram of the data structure for the World Coin Database. Click on each block to see its definition.

Materials are the raw materials used to make a coin, typically elements, or alloys if their exact constituents are not known.
Tags are individual images or objects found in a design for the purposes of identification.
The World Coin Database categorizes tags into a hierarchy so both generic and specific tags can be searched.
Tags are based on the appearance of objects, and one tag may include many synonyms or words that identify visually similar items.
Exchange rates are applied between a currency that is being replace and the currency that is replacing it.
Compositions are a combination of materials, including the relative amounts and where those materials exist.
Materials can located in the "core" of the composition, as well as in a outer layear via plating or cladding.
Each composition is assigned a color, magnetism, and optionally a nickname.
While most coins are circles, many have rounded corners and sides, or even holes.
Each side of a coin has a design, which is an artwork usually consisting of one or more of: the name of the country, denomination, and imagery or symbols of importance.
Each coin in the World Coin Database is made for a specific currency by the country or issuer.
Planchets are the prepared compositions, in the appropriate shape, ready to be struck into a coin.
Obverse and reverse refer to opposite sides of a coin.
The determination of which side is which is decided by the issuer, or through conventional wisdom.
The orientation of a coin is the alignment relationship between the obverse and reverse sides.
Orientation is either medallic ("tops" of designs are in the same direction) or coin ("tops" of designs are in opposite directions).
The edge of a coin is the outer surface perpendicular to the obverse and reverse, and is usually plain/smooth or milled/reeded, but may include designs or text.
The edge should not be confused with the rim, which is the raised perimeter of the obverse and reverse.
The country, or issuing organization, is the entity who commissioned the manufacture of the coin and put it into circulation as currency.
The denomination is amount of currency, including the unit (or subunit/superunit).
The coin is finished product from striking designs onto a planchet and issuing it as currency.
Categories are various other topics used to describe or group coins based on their content or purpose.
Mintages are the amount of coins made or issued, usually specified by year, and sometimes by mint or variety.
References are other sources of information to learn more about the coin.

Shapes

For clarity, here are some definitions regardings coin shapes and their characteristics. All coins in the World Coin Database (so far) are regular polygons, being both equiangular and equilateral.

  • Curved - The sides are curved instead of straight.
  • Rounded - The corners are rounded instead of sharp.
  • Diameter - For non-circular coins, the diameter of the circle inscribed by the shape.
    • Dodecagon (12 sides) - Measure between farthest vertices. If measuring between farthest non-curved sides, divide by cos(π/12).
    • Reuleux - Same as diameter.
    • Scalloped - Measure between farthest projections.

Tags

  • All tags are singular, but use optional metadata to describe the part (head/bust, top/bottom, etc.), orientation (left, right, etc.), and count (integer).
  • Dots or similar common decorations that continuously span the entire perimeter of a design are not tagged.
Original text and images ©2010–2021 World Coin Database