AFAIK there are few pure sources of dolomite lime on the market. Agricultural or garden lime is virtually all calcitic or
dolomitic.
Dolomitic is distinguished from
dolomite, it does not contain as much Magnesium and the analysis I presented is typical of a dolomitic lime: not out of balance at all, 12% MgCO3, 3% Mg (10:1 Ca:Mg).
But that begs the question, what would the 'correct' ratio be? And what about the total ratio of Ca to Mg in the soil itself? Since we'd have to consider everything else in the mix. According to my resarch, though, it really doesn't matter so much.
The information in the following quote isn't strictly correct. Most notably, the descriptor "elemental" is used incorrectly.
Dolomite lime does not contain "elemental" Calcium, neither does Gypsum (which is hydrated calcium sulfate or CaSO4·2H2O, period.) That is not how gypsum works, and in fact gypsum itself
is not a good liming agent (it is typically used to add Ca to soils that already have a high pH).
In chemistry when something is "elemental" that means it is in its most basic, most naturally stable form. Elemental oxygen is diatomic O2 (an oxygen double bonded to an oxygen) while Ozone is another (triatomic) elemental allotrope of Oxygen (O3). Elemental Chlorine is most typically diatomic Chlorine gas Cl2, elemental Hydrogen is H2 (Hydrogen gas) while elemental Sulfur is more typically octatomic S8 (8 atoms of Sulfur each single-bonded in cyclic conformation). S2 is very rare, since S=S [double] bonds aren't strong like O=O bonds are. The most stable elemental S8 occurs as orthorhombic crystals.
Dolomite as a mineral is usually expressed CaMg(CO3)2, or (CaMg)(CO3)2 and referred to as calcium magnesium carbonate. It does not contain elemental Calcium 'tightly bound' to anything. As a matter of fact, elemental Calcium does not exist in the natural world. Dolomite is actually referred to as a
double carbonate salt. The crystal lattice structure is trigonal-rhombohedral, just like calcite, except that the Calcium and Magnesium ions are alternating in the lattice. Sometimes instead of a magneisum ion there is an iron or magnanese here or there, giving the material a different color.
Coot was wrong, unfortunately, and that wouldn't have been the first time.