0

Recently, I read through this sentence in my book.

Limestone is found in association with rocks composed of calcium carbonates or calcium and magnesium carbonates.

I want to focus on this last part: calcium and magnesium carbonates

I thought that this could be two things. Either calcium carbonates and magnesium carbonates, or calcium AND magnesium carbonate.

In most cases, the first meaning would be the appropriate meaning and most would read it that way. What would be a good way to express the second meaning?

9
  • I couldn't think of a better title, so I would welcome suggestions for a better title.
    – Zero Fiber
    Commented Mar 22, 2015 at 14:49
  • Limestone is surely a naturally occurring form of calcium carbonate. Commented Mar 22, 2015 at 14:59
  • Dolomite is 'an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally CaMg(CO3)2', according to Wikipedia. Commented Mar 22, 2015 at 15:12
  • The only really unambiguous way of expressing the second meaning would be to switch the constituents: “… rocks composed of calcium carbonates or magnesium carbonates and calcium”. Even that is not quite unambiguous, though: is it then (1) rocks composed of (a) calcium carbonates or (b) magnesium carbonates and calcium; or (2) rocks composed of calcium and (a) calcium carbonates or (b) magnesium carbonates? Complete and clumsy unambiguity: “rocks composed of either (a) calcium carbonates; or (b) magnesium carbonates and calcium”. Commented Mar 22, 2015 at 15:17
  • Calcium would not exist naturally: it's too reactive. Commented Mar 22, 2015 at 15:20

3 Answers 3

1

To express the second meaning, I would write:

Limestone is found in association with rocks composed either of calcium carbonates or of magnesium carbonates and calcium.

3
  • But ... there's a big difference chemically between calcium and calcium carbonate. Commented Mar 22, 2015 at 21:44
  • @PeterShor: Expressing the unlikely reading unambiguously is exactly the point of this answer.
    – user86291
    Commented Apr 23, 2015 at 7:57
  • In fact, that's the OP's question, which I didn't read carefully enough. Commented Apr 23, 2015 at 10:36
0

Structuring the phrases consistently -- making both of them prepositional phrases -- would likely clear the air.

Limestone is found in association with rocks composed of calcium carbonates or of calcium (carbonates?) and magnesium carbonates.

0

If you mean "calcium magnesium carbonate", call it that.

If you mean "calcium carbonate and magnesium carbonate", either call them that, or if you wish to shorten it, say "carbonate of calcium and of magnesium". (You could say "carbonates", but some readers might construe this to mean there are multple types of calcium carbonates and/or magnesium carbonates —are there?)

Compare MAALOX, which contains both aluminum hydroxide and magnesium hydroxide. One could say it contains "hydroxide of aluminum and of magnesium"

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.