Rai stones
Where: Island of Yap, Micronesia
When: 500 AD - today
Value: Each stone has its own unique value
These large and round discs are carved from limestone and used as currency on the Micronesian island of Yap.
The stones have different values that depend on their history rather than their size. For example, the more people who died transporting the stone, the higher its value will be.
Tea bricks
Where: China, Mongolia, Tibet, and Central Asia
When: 19th century - 1935
Value: Varied depending on the quality of leaves and the distance and accessibility of the market
Tea bricks are blocks of ground tea leaves that are packed into molds and pressed. The bricks were used as a form of currency up until the beginning of WWII, when the value of tea skyrocketed in many parts of Asia.
Tea blocks were actually said to be favored over coins in places like Siberia and Tibet, as they could be used to treat coughs and colds or even eaten if food was scarce.
Canadian Tire money
Where: Canada
When: 1958 - today
Value: 5¢, 10¢, 25¢, 50¢, $1 and $2 denominations
Created by Canadian Tire back in 1958, this money was originally conceptualized as a customer reward tactic.
Customers would get coupons that featured a tire and dollar sign running hand-in-hand. The concept became so popular that other businesses began accepting Canadian Tire Money as well.
Parmigiano-Reggiano
Where: Emilia Romagna, Northern Italy
When: 1953 - today
Value: 300 euros (around $341) per wheel
Italian bank Credito Emiliano accepts Parmigiano-Reggiano cheese as collateral for loans, helping to assist cheese-makers during periods of recession.
The bank's warehouses are said to hold as much as 17,000 tons of the cheese, which is valued at around $187.5 million in total.
Each wheel of the cheese has a serial number so that it can be traced if it is ever stolen. The bank allows loans for as long as 34 months, which is equal to the approximate time it takes for the cheese to age.
Bottle caps
Where: Cameroon
When: 2005
Value: Varied depending on the prize
In 2005, a brewery in Cameroon started a competition where buyers could win prizes placed under beer caps.
Other companies started offering the competition as well, and prizes started to come up in almost every cap. The prizes on offer ranged from mobile phones and luxury cars to more beer. People even used them to start paying for taxi rides.
Shell money
Where: Langa Langa Lagoon, Solomon Islands
When: Archaeologists believe that shell money could have been in use as early as 1200 B.C., and it's still in use today
Value: One string of shell money is worth 1,000 Solomon dollars
In the Langa Langa Lagoon, located in the Solomon Islands, shells are often used to create jewelry pieces that are traded, used as peace offerings, or offered during bridal ceremonies.
Since the shells have become increasingly rare over time, their value has also increased.
Shire Silver
Where: New Hampshire, USA
When: 2007 - today
Value: Value can fluctuate with the prices of gold and silver
Shire Silver is made with a small amount of gold or silver and is roughly the size of a credit card.
It started as a local currency in New Hampshire, though its creator claims to have received orders from all over the world.
Mobile phone minutes
Where: Various countries, including Kenya, Nigeria, Egypt, Zimbabwe, and Romania
When: 2011 - today
Value: The value of the airtime being transferred is equal to the value of the items or goods being purchased (1:1)
In several countries around the world, people are using their pre-paid mobile airtime minutes in exchange for cash, or as barter for goods and services.
Often, the pre-paid minutes can be swapped or spent in shops for small transactions.
Notgeld (emergency money)
Where: Germany, but there have also been instances of this in Ireland, Sweden, Belgium and France
When: 1914-1923
Value: Much like banknotes, where the value was printed on the item
"Notgeld", a German word for "emergency money", was used during the beginning of WWI because there was a shortage of metals that could be used for coins (though cases of this can go as far back as 1689 in countries like Ireland).
While it was used from 1914-1923, the period of 1922-1923 is considered to be the peak of its use in Germany. So much Notgeld was issued during that time that further measures had to be taken to issue them in the form of silk and cards.
100 Quintillion Pengo
Where: Hungary
When: 1946
Value: $0.20
After WWII, Hungary saw its prices begin to nearly double every 15 hours, causing the country to experience the highest rate of hyperinflation to ever be recorded.
The 100 quintillion pengo was the largest denomination bank note to become legal tender, with a value of around $0.20.