I notice that people often use "gold" and "diamond" in lower case. Yet as far as I see it these are all "proper names" of an abstract idea and really ought to be capitalized. Am I in the wrong here?

This answer addresses it by stating "chemical element names are common nouns". But why are we so sure that's true?

Proper nouns are initially defined as an individual person, place, or organization. However you can push the envelope for example by naming your table "Michael". No you wouldn't call the table "michael" ever. It has a proper name, thus you would use the proper name as a proper noun. Eventually this gets to the notion of an "element". I feel that whenever we use a name as an identity then it is a proper noun. It is the difference between "I bought some gold." versus "The element Gold is the 79th element". In the latter case, Gold is serving as a name and an identity whereas in the former gold is merely the object itself.

This arises from an extremely petty concern of mine regarding a discussion about whether its improper to capitalize "Diamond" in: this question title but I wanted to know for sure if I'm in the wrong.


4 Answers 4


It's convention.

Take a few similar sentences:

I gave it to a person called Michael.
The 79th element is called Gold.
I put it on the thing called Table.
There are many Tables in that room.
There are many Michaels in the world.

We don't give tables a name like that: table is a common noun. People and places do get names.

The metal we've called gold is a common noun. Yes, it's a name; we don't say *a gold like a table, but it's not a proper name.

Convention has changed. In times past, it would have been capitalised, but still distinguished from proper names which were capitalised and italicised. Even here, it's not a proper name.

Juno, embrac'd, and hugg'd a deformed and ill-favoured Cloud: And discover no more true wisdom than Children (whose Reason moves but in the lowest Sphere) while they prefer some Pebble-stones or Painted-glass, before the most bright Orient Pearls, the richest Jewels, and purest Gold.

A discourse of the excellency of the heavenly substance which is useful for the present, and so may be for future times, John Hickes (1633–1685) via University of Michigan

  • 2
    I agree with your arguement but your examples are quite confusing.
    – Lambie
    Commented Apr 22 at 15:25
  • 10
    The reason we don't say "a gold" has nothing to do with "gold" being a name, it's about the distinction between countable and non-countable nouns. An ounce of gold, a cup of milk, a grain of wheat-- but not "a gold", "a milk", or "a wheat". "Two cows" yes, but not "two beefs"-- rather, "2 pounds/slices/boxes/heaps of beef".
    – Jay McEh
    Commented Apr 22 at 20:05
  • 2
    @AndrewLeach Because I don't have a better answer to offer than what has already been given by you and others. I just take issue with the implication that "gold" is a name and "table" is not, in any way relevant to the topic. I thought the purpose of comments was to suggest improvements/clarifications to answers?
    – Jay McEh
    Commented Apr 23 at 12:27
  • 2
    I'm with Jay on this. Your answer is mostly good, except that it's confused by your use of "a gold" to illustrate the problem, when in fact it's just the incorrect article for an uncountable noun. You should say "the gold" (or use any other article appropriate for use with uncountable nouns).
    – JakeRobb
    Commented Apr 23 at 17:30
  • 1
    May be worth clarifying the ‘times past’: the trend for capitalising nouns was relatively brief — in the late 1600s and early 1700s — and was not present in Old English or Middle English, nor in the last couple of centuries.  See this question.
    – gidds
    Commented Apr 23 at 18:17

Generally, the names of chemicals are not considered proper nouns. They are classified as common nouns:

Proper nouns name specific people, places, organizations, or things (ex: John, Paris, Apple, Mount Everest).

Common nouns name general classes of people, places, things, or ideas (ex: boy, city, company, mountain, ground).

Chemical names refer to broad categories of substances with shared properties, rather than a unique individual entity.

Example: "Sodium chloride" is not the name of one specific batch of table salt, but rather a generic term for the chemical compound.

However, with aspirin (being the common noun) there is Bayer aspirin, being a Proper noun. So, brand names, and trademark names are different than common referenced.

There are always the difficult to qualify, for example, Xerox. This is the name brand/trade name of a copying machine. IBM and Hewlett Packard both make copy machines as well. However, in the sentence "Would you xerox this for me?" which means to make a copy for me, it is lowercase because their Trademark has been ground down to dust by marketing into a generic/common name reference for copying.

Genericide: The trademark becomes so widely used as a generic term for the product that it loses its distinctiveness. Courts may rule that it's now a common noun, no longer exclusively owned by the company.

  • One issue with this answer. In the sentence "There are two Marys in our class," is "Mary" a common noun? After all, it's not naming one specific person; it's denoting the class of people who are all named Mary.
    – alphabet
    Commented Apr 22 at 12:39
  • 2
    This answer randomly capitalizes words.
    – JRE
    Commented Apr 22 at 13:52
  • 1
    @JRE I'm not seeing randomly capitalized words. Could you give some examples of what you mean?
    – user888379
    Commented Apr 22 at 14:58
  • 3
    " being a Proper noun. "
    – JRE
    Commented Apr 22 at 15:14
  • 1
    I assume you mean Apple the company, vs apple the fruit?
    – CGCampbell
    Commented Apr 23 at 12:56

In scientific journals, especially those on the topic of chemistry, a style guide is likely to be followed for formatting of chemical names. For modern scientific literature, most follow the International Union of Pure and Applied Chemistry (IUPAC) style guide, which says:

Chemical names are not capitalized unless they are the first word of a sentence or are part of a title or heading. Then, the first letter of the syllabic portion is capitalized, not the locant, stereoisomer descriptor, or positional prefix.

The works in the popular press may not follow such rules precisely and non-chemists are likely to be confused by the prefixes. However, articles in the popular press based on scientific literature are likely to be influenced by its usage. For instance, the New York Times appears to follow this convention, capitalizing methyl isocyanate in the title, as with ordinary words, but leaving it lowercase in the body of the text.

In the context of scientific usage, capitalization of chemical names has been discussed on Chemistry Stack Exchange.


Most substances' names are not capitalized unless they are trademarked. Most trademarks are capitalized, though the owner of a trademark may specify otherwise. Some names were trademarked at one time, but have since become generic; such names often become lowercase, but not always. Product names which are derived after an inventor's name will often remain capitalized, though not always (e.g. the petroleum distillate used to power trucks and locomotives is called "diesel" rather than "Diesel" even though it's named after the inventor of the four-stroke compression-ignition engine for which that fuel was formulated).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.