Called Mint, the series of 'coins' have been given values according to the amount of time invested in extracting the material and fabricating each object.
Here is some more information from William Smith of Smith & Wightman:
MINT is a series of objects of different value that operate as a currency. The objects have accrued their value through the amount of time invested in them.
Time embedded in the material (through harvesting/ extracting and processing) and then time spent in fabrication.
In making this collection of objects, and clearly stating their relative value, we ask how much of the value of an object resides within it, and how much is brought to it by the potential owner?
Why do certain forms or materials look more expensive than others? What is the value of an object with no apparent function?
Mint’s monetary units have been designed using the following principles:
They must fit in one hand so as to be easily exchangeable
They must be readily reproducible
They must be durable and non-perishing
They must not rely on additional objects to operate (eg. Batteries)