This one has puzzled me for quite a while now and not sure I have ever seen the answer.
So the Oxford Dictionary defines Ceramics as "made of clay and hardened by heat"
There is no clay in what we all here call "ceramic chips", they are simply a hardened plasctic blank. As a matter of fact what we do call "clay chips" fits the definition of "ceramic" perfectly....
Enlighten me Amigos?
We call ceramics "ceramics" even though they're made out of plastic because the particular plastic they're made out of is very hard and very smooth (unless deliberately textured) and accordingly looks and feels
somewhat like they're made out of ceramic. I'd be curious to know how and when that name first got used for those chips... Chipco made the first ones, I wonder if they were ever deliberately marketed using the term "ceramic" or if the customers (casinos, dealers, maybe even players) just started calling them that.
Clay chips aren't clay in the same sense that bricks and pottery are, and clay chips definitely aren't any sort of ceramic (clay like in bricks and pots is a type of ceramic). Clay chips are basically plastic, but the formula for the plastic includes some minerals, which contributes to the way they feel.
The difference between clay-like-in-bricks and clay-like-in-poker-chips is that clay-like-in-bricks is soft when
wet and hardens as it's
dried, i.e. its properties depend on how much moisture there is. Clay doesn't melt as its heated; it becomes drier and drier as its heated until it is completely dry, at which point it's fully hardened and waterproof. Whereas clay-like-in-poker-chips doesn't behave like clay, it behaves like
plastic (because that's mostly what it is). It's firm at low temperatures, but softens and melts at higher temperatures. When heated
enough under high pressures, it undergoes a physical change called
curing which makes it hard again, permanently, so that even once it's cooled down, it won't melt again when heated again. This is in some respects similar to the change that clay-like-in-bricks goes through (they both have a permanent change and become permanently rigid) but the details of what's actually happening and how it works are very different. Clay hardens when the water is driven out; plastic (i.e. clay-like-in-poker-chips) hardens because the polymer molecule chains get "cross-linked" aka tangled up with each other.
The reason clay chips are called "clay" is because the very earliest clay chips were made by mixing natural plastics (lacquer resin) with clay (i.e. dirt) in an effort to make something similar to ivory - something pliable and moldable at first that would then harden and could be cut and polished and carved. Later the natural plastics were replaced with synthetic plastics, starting with the first synthetic plastic developed: celluloid. Poker chips of this sort have always contained clay, but the clay served as a sort of filler to give the plastic greater density and an appealing feel (again, trying to replicate ivory); chips were never made of clay the way that bricks and pots are made of clay.