Frequently Asked Questions

What does 'Fineness' mean?

Contrary to what the common citizen many times thinks, the jewelry items are not made of fine precious metals.

In fact, precious metals in that state are very difficult to work. If a single wedding ring, for instance, were to be made of fine gold, its resistance to deformation would be so insignificant that the usual every day activities of a common user would be enough to constantly produce damage.

Therefore, the jewelers needed to add other metals, in addition to the usual precious metals with which they worked, in order to obtain an adequate alloy for the kind of work they intended to produce. The quantity of precious metal in the alloy is indicated by its fineness, meaning that the higher is the fineness of a jewelry item the higher is the quantity of precious metal per mass unit existing in that same jewelry item.

Quoting J. Almeida Costa and A. Sampaio e Melo (in Dictionary of the Portuguese Language) one can say, then, that the fineness is the percentage of pure metal in an alloy, in which it's fundamental. The word "title" ("título" in portuguese) is used many times instead of fineness.

What are the thousandths and the carats?

The fineness is usually described through thousandth or carats, although the thousandths are each time more used, since they are easier for a consumer to understand.

For instance, when an item has a fineness of 750 thousandths (750‰) the information that is being passed to the eventual buyer is that in 1000 units of alloy mass there are 750 units of pure precious metal. Nevertheless, if carats are used to convey the same information, one should say that it is an item with a fineness of 18 carats, what is more difficult for a common consumer to understand.

These are the following equivalences between thousandths and carats:
333‰ mean the same as 8 Qt;
375‰ mean the same as 9 Qt;
417‰ mean the same as 10 Qt;
585‰ mean the same as 14 Qt;
750‰ mean the same as 18 Qt;
800‰ mean the same as 19.2 Qt;
1000‰ mean the same as 24 Qt.

Other useful information:

It's impossible to detect what is the fineness of a given item only by looking at it, meaning that a 333‰ article, for instance, can be absolutely identical to a 800‰ article only in appearance. Maybe it was this fact that produced the popular saying: "not all that glitters is gold..."

What is the origin of the expression "sterling silver"?

The expression "sterling silver" – used to describe the silver of 925‰ – goes back to the XII century. It was invented in England, when King Henry II had to fetch refiners of precious metals from a region in Germany, known as Easterling. The result of the work of those refiners had such a quality that it started to be used as money, in 1300, and it became known as sterling silver.

What marks must the legally traded jewelry items have?

In order to properly comply with the law, the jewelry items traded in Portugal must have two marks: one, punched by the producer, identifies him, and another one, punched by an assay office, authorised by the Portuguese State, guarantees the fineness of those items.