Bonhams will sell the Tacasyl Collection of Magnificent United States Proof Gold Coins as part of its September 23 auction in Los Angeles.

The collection contains nearly every major gold design type issued in proof in the US between 1836 and 1915.

Bonhams states that each of the 27 lots "could be considered a highlight in its own right", with each coin either the finest known example or the finest of its type. The majority of those offered have been cited in standard reference books as a testament to the rarity or condition.

Graded by NGC, the least well preserved coins (of which there are two) have been given a grading of Gem Proof-65. Nonetheless, each is still the finest known of the date or tied for the title with another example.

The Stellas of 1879 and 1880 were created as a failed attempt to produce a coin that could be used in international trade

The highest graded example of the selection is a Saint-Gaudens 1907 high-relief double eagle, which has been awarded an outstanding Proof-69.

"When I first saw the collection I was staggered not only by the exceptional quality of each coin, but by their individual rarity," said Bonhams' Paul Song, director of rare coins and medals at Bonhams.

"I am in awe of the collector who assembled these coins; his emphasis on quality was paramount, and his success at having achieved his goal is unquestionable."

The standout coins of the sale are a set of four "Stellas", $4 coins that were produced in 1879 and 1880 at the Philadelphia Mint in an unsuccessful effort to create a coin that could be used in international trade.

Each of the four on offer has been graded Proof 67 and are the finest of their kind, with estimates ranging from $200,000-$1.5m.

See some of the superb gold coins for sale in our online store for the latest addition to your collection.