Because it's shiny and expensive looking, no other reason than to be visually pleasing would be my guess.it is easier to handle if it is suspended in the gold ingots.
Latinum is not literally "pressed" in or by gold. "Press", in this context, comes from the British dialect of English, a reference to a wooden cabinet which contains linens. In Star Trek: Deep Space Nine, it is shown as a mercury-like substance suspended inside ingots of gold bullion. The Ferengi are not much into fiat currencies or commercial paper.
The actual meaning of the term peressed in this context is from the latin pressare "to press," frequentative of pressus, p.p. of premere "to press, hold fast, cover, crowd, compress," from PIE *prem-/*pres- "to strike." Latinum, while not normally able to be replicated, could be synthisized, and for this reason, real latinum was 'struck' with an identifying mark, just as gold legally mined was struck by governments in the past. The governments seal proved that the gold was legal tender. Likewise, the latinum being sealed in a solid container, and stamped with a identifying serial code let a banker know that the latinum was in fact real, and not contraband.
The material used to create the mark could be anything of course; it is probably Ferengi avarice that accounts for gold being used.
Is this canon or are you just making this up?
So you don't have to make change with an eyedropper. Admiral William Thomas Riker 01:29, August 4, 2011 (UTC)