Classical Numismatic Group's online auction provided a great history lesson with the sale of a rectangular 1902 Tercentennial of L’Escalade silver medal that sold for $177 June 15.

A Proof .999 fine silver dollar and Proof .9999 fine gold $100 coin with similar designs issued for Niue feature the koala, which is a popular feature of coins marking the region.

A Proof .925 fine silver €20 coin has been issued by Austria featuring a convex/concave design to best exemplify the astronomical phenomenon known as a black hole.

Even though the euro replaced Irish currency more than 20 years ago, the Central Bank of Ireland is still seeing paper money and pound and pence coins being offered for exchange.

The art of Mary Gillick, who provided the original portrait of Queen Elizabeth II for coinage, is on display in a British Museum exhibit during the queen's Platinum Jubilee, and is subject of a new book.

The 1947 recovery of an object in Roswell, New Mexico, sparked worldwide interest in unidentified flying objects, and event's 75th anniversary prompts gold and silver coins from Niue.

Unique packaging for ancient, curved and other irregularly shaped coins is now available after two years of research and development into the product for protection of special coins.

Two private minters are offering an array of coins, including several gold and silver selections, designed to add to the celebration of Queen Elizabeth II's historic completion of 70 years of rule.

Tipping the scales at 15,030 grams and measuring 220 millimeters in diameter, the largest gold coin ever made by the Royal Mint has been commissioned by a private collector to celebrate Queen Elizabeth II's reign.

For over 20 years, content on the Sixbid.com online auction platform was available in English and German, but the site has expanded to include six additional languages to better serve customers.