What Is a Coin Reference?

A coin reference is a citation to a published book or catalog that describes a particular coin type. Think of it like citing a page in a history book.

Rather than writing out an entire description every time, dealers, auction houses, and collectors simply reference the standard catalog where the coin is published. A reference tells other collectors exactly which coin type is being discussed.

Why Do References Matter?

References give collectors a precise, shared shorthand.

Instead of saying "the silver coin with the emperor holding a spear," a collector can simply say RIC II Trajan 123. Anyone with access to that reference can immediately understand which coin type is being discussed.

The Most Common References

A handful of catalogs come up again and again. Here are the ones you'll meet most often, and what each one covers.

RIC, Roman Imperial Coinage

RIC is the standard multi-volume reference for Roman Imperial coinage from Augustus through Late Antiquity. Most Roman imperial coins offered by major dealers include a RIC reference.

RPC, Roman Provincial Coinage

RPC covers coins struck by cities and provinces under Roman rule. These coins often feature local deities, city symbols, and Greek legends rather than the standard imperial coinage. If you collect Roman Provincial coins, you'll encounter RPC frequently.

Sear

David R. Sear has authored several of the most widely used reference books for collectors of Greek, Roman, Byzantine, and Biblical coins. His books are especially popular because they are written with collectors in mind while maintaining strong scholarly standards. Many dealers include Sear numbers alongside other references.

HGC, Handbook of Greek Coinage

The Handbook of Greek Coinage (HGC), written by Oliver D. Hoover, is a modern reference covering Greek coinage by region. Many dealers and auction houses use it because it is comprehensive, well organized, and relatively easy to navigate.

BMC, British Museum Catalogue

The British Museum Catalogue (BMC) is a series of reference volumes covering numerous ancient coinages. Although many of the volumes are more than a century old, they remain important scholarly references and are still cited today.

SNG, Sylloge Nummorum Graecorum

Rather than being a single book, SNG is a long-running series documenting Greek coins from museum and private collections around the world. Many collectors use SNG references to compare photographs of known examples.

RSC, Roman Silver Coins

RSC (Roman Silver Coins) is another reference you'll occasionally encounter, particularly in older auction catalogs and dealer listings. Although newer references are often preferred today, many collectors still recognize and use RSC numbers.

Are References the Same as Rarity?

No. A reference number simply tells you where a coin is published. It does not automatically mean the coin is rare, valuable, or especially desirable.

Some of the most common Roman bronzes have RIC numbers. Some of the rarest Greek coins also have reference numbers. References identify coins. They do not determine their value.

Why Do Some Coins Have Multiple References?

Many ancient coin types appear in several different books. For example, a Roman denarius might include several at once.

Each reference serves a slightly different purpose. Dealers often include multiple references so collectors can locate the coin in whichever catalog they own.

You'll also occasionally notice that different books assign different reference numbers to the same coin type. As new research is published and older catalogs are revised, reference numbers sometimes change or expand. That's perfectly normal.

Do You Need These Books?

Not all of them, but I do recommend owning at least one. A good reference book teaches you far more than just how to identify coins. It helps you understand rulers, mints, denominations, legends, and the history behind what you're collecting. For many collectors, a reference book becomes just as valuable as the coins themselves.

You don't need an entire library to get started. One well-chosen reference book on your favorite area of collecting is often enough. As your interests grow, your library will naturally grow with it. Many experienced collectors build their libraries one book at a time while also using online databases, museum collections, and auction archives to supplement their research.

Start Your Library

If you're ready to purchase your first reference book, here are a few excellent places to begin.

As your collection becomes more specialized, you'll naturally discover additional references tailored to your interests.

My Advice to New Collectors

Don't let a string of abbreviations intimidate you. They're simply shortcuts that help collectors communicate more precisely. Every experienced numismatist started exactly where you are now, wondering what those letters meant. Over time, you'll begin recognizing them naturally. Eventually, you'll see RIC, RPC, Sear, or HGC and immediately know what kind of reference is being cited.

One of the best investments you can make as a collector isn't always another coin. Sometimes it's a good book.

Every book you read makes every coin you own a little more meaningful. That's one of the milestones that marks the transition from buying ancient coins to truly studying them.

History wasn't just written. It was minted.