This is a small disk of high purity Tin metal (Sn) 9999 parts per 1000 pure that has been chemically etched to show its internal crystalline structure. This product is great for collectors and educators, these are safe to study and handle for students of any age as Tin is considered non toxic.
Each and every one of these disks is unique with no two patterns quite the same. The examples photographed here are a good representation of the different examples, they are photos of our actual stock but yours may differ slightly depending on stock in hand at the time. Please note that this listing is for one disk, the photos showing several are for reference.
These are cast into a mold and have a flat side and a rounded side, both show different patterns (different cooling speeds). The rounded side will almost always have a little rough spot or folds/dimples where the last bit of tin and a little slag pours in (the slag etches away leaving the rough bit). Each one is selected at random from our stock. Rough handling may scratch the etched surface
These are 16mm across by around 6mm thick and the weight is around 6.5 to 7 grams (the thickness and therefore weight vary a bit, the above are typical but it will vary, we cull any small, light castings though so yours won't be much lighter and may well be bigger.