What is a Hallmark vs. a Trademark

A Hallmark is a country sanctioned, guarantee of quality mark
A Trademark is a maker's or responsibility mark

Hallmarks

Refining of gold dates back thousands of years.  In more recent times the mixing of other metals into pure gold and silver defined karat gold and the purity of silver.  Late in the 13th century, in an effort to protect the public from misrepresented wares, England introduced into law a basic marking system that would guarantee an item's minimum purity to be better than the coinage in use. This would also eliminate the unlawful practice of melting of coinage to produce items of precious metal.  The first mark in use at that time was the leopard's head.  With time, more marks were added identifying the assay office, year of manufacture, maker, purity and on special occasion even a commemorative mark.  England was first and most systematic in their method of marking from the beginning through to the today.

The term Hallmark came about from the English that would seek an assay mark for their items of precious metal from 'The Goldsmiths Hall' one of the first assay offices in England, thus the shortened term "hall-mark" evolved.  In time, other countries followed with the practice each having their own methodology of "Hallmarking".  As a note, the United States has never developed a method of assay for the hallmarking of precious metals items made in the U. S..
 

Here is an example of an English made item that shows (from left to right)
a maker's mark or trademark "W C" for W. Comyns & Sons in London, the
lion passant representing the country's sterling silver standard for England at the
time, the leopard's head representing the London assay office (where these marks were
stamped) and a uniquely stylized"R" that is a date mark that represents
the year of assay ~1892-3. 

Trademarks

Trademarking is the practice of marking an item made of any material with the signature or logo of the maker, manufacturer or sponsor (Tiffany & Co, Mattel, Levi, etc.).  In the U.S.A., it is referred to as the brand which makes the consumer rely in the guarantees of the maker for consistency in quality.  In many countries, the maker's mark is the responsibility mark representing the responsibility of that maker to guarantee the quality of the item to be as marked. 

Here in the United States, no mark is mandatory on any item of precious metal but if a maker chooses to place a fineness or standard mark (14k, 18k, etc.) on an item, then it is mandatory that there be a mark from the maker to show who is responsible for the guarantee of claimed fineness. In the jewelry trade, this mark is called a "trademark".  In other countries, it is called a maker's mark, responsibility or sponsor's mark and may be present along with the hallmarks that a country may punch in accordance to their system of marks.

This is an example of a "trademark" and fineness mark from the
famous house of provenance "Tiffany & Co.".  Tiffany's, as
well as other houses of provenance will mark the item with
their name and the fineness of the metal.

The Hallmark Research Institute concentrates on hallmarks. Due to large numbers of sparsely
documented and accessibly challenged manufacturer's markings, it is difficult
to trace many maker's marks. Our services are limited in this area.
For other sites that concentrate on maker's marks, please visit our Links page.