A fountain is a spring of water. The term may refer to a stylized heraldic charge, or to a naturalistic structure. The unmodified term refers to an heraldic charge, found in the arms of Stourton, 1411 [DBA2 391], and defined as a “roundel barry wavy argent and azure”. When used in a blazon, it’s unnecessary to specify the fountain’s tinctures; as with bezants, the tinctures are part of the definition. If tinctures other than azure and argent are used, the whole must be explicitly blazoned: i.e., one does not blazon a “fountain vert and Or”, but rather a “roundel barry wavy vert and Or.”
When specified as “natural” or “of three tiers”, the term refers to a stonework edifice spouting water. It too is a period charge, found in the arms of de Fontana, mid-15th C. [Triv 146], and of Newpruner, 1605 [Siebmacher 218]. The natural fountain doesn’t have defined tinctures, as the heraldic fountain does: they must be explicitly blazoned. For related charges, see roundel, well.
The Baron of Fontaine dans Sable bears: Argent, in pale a three-tiered fountain sable spouting azure and a laurel wreath vert.
Yseulte Trevelyn bears: Gules, three fountains.
Um Rashid Kathira bears: Or chapé ployé counter-ermine, a fountain.