Concrete is one of the main components of an urban jungle. Concrete is, in our world, everywhere. It’s pretty darn sturdy.
Concrete is a mixture of cement, water, and aggregate. The material of that aggregate can vary, though it usually accounts for about 60 to 75% of concrete - the rest is the cement and water. The cement and water is what gives it strength. The aggregate is the creative piece of the puzzle. The amount and type of aggregate varies depending on what the concrete will be used for and made into. It dictates how rough or beautiful it will look. It changes whether that concrete can be used for sidewalks, the walls of skyscrapers, or fine jewelry.
Usually, fine aggregates are made of crushed stone or natural sand, and most of these tiny particles will pass through a 3/8 inch sieve. Course aggregates are any particles greater than .19 inch, but generally are between 3/8 of an inch and 1.5 inches.
Concrete has been around since ancient times. In fact, the outer dome of the Pantheon in Rome is the largest unreinforced solid concrete dome on earth. It has been since 27 BC. So it is a pretty committed material.
Our concrete coasters are indeed made of concrete. The mix we have has taken years to develop. While strong, concrete has a tendency to crack and break. And, finding a mix fine enough to make small household items like coasters out of is actually pretty difficult.
The mix itself is actually quite simple - cement, water, sand, granite dust, and carragenan. However, these elements need to be combined in very specific amounts to create the perfect mix.
Carragenan is something you probably won't find in concrete, ever. It is derived from seaweed, and found in tons of everyday products, from ice cream to toothpaste. This element gives the cement the right viscosity and aids in the process of curing the cement and water.
The resulting concrete is smooth to touch. And you will find many tiny imperfections - no two coasters are exactly alike. The granite dust that is used to create the coasters contains varying degrees of darkness, so the concrete will be lighter or darker depending on the mix.
Concrete is both utilitarian and aesthetically pleasing. Our coasters are a very specific breed of unique - hand-crafted and designed in our image of all that concrete can be.