All of the stones shown here are Japanese clamshell. The sets include 181 stones for black and white. The black stones are all Japanese slate, but are not pictured as they all simply appear as black circles. They are all in the antique category, as Japanese clamshells of sufficient thickness are now extinct. The actual age of the stones are mostly pre-WW2, with some still older.
As I do not have professional measuring equipment, the thickness dimensions shown have a slight plus or minus factor. The diameter of all the stones is standard, so the apparent size changes shown in the photos are not meant to be accurate, but merely show the grain.
Shipping is included for Australia, and is a flat $67 for the rest of the world.