How to distinguish the buttons of different materials?

Button materials are roughly divided into plastics (resin, plastic), metal buttons (copper, iron, alloy), natural (shell, wood, coconut shell, bamboo. All kinds of materials are made into buttons, and the process is not The same. Some buttons look the same, and even industry people may not be able to distinguish them with their eyes, so if they are damaged, they can be distinguished by scraping their outer clothing.
Buttons are divided into Plastic Buttons and resin buttons, plastic buttons and resin buttons, plastic (including various plastic) buttons are generally die-cast, so there will be a line on the side of the button, this mold line, some factories may be in This line is removed in subsequent processing, but its weight will be lighter than resin (of course, some special plastics will be heavier). Resin buttons are mechanically carved and then polished, so there is no full mold line on the surface, which is very smooth. However, it is fragile, the surface is easily scratched, and it will become soft in boiling water.
How to distinguish between copper buttons and iron buttons?
Buttons made of copper and iron. You can find this with a magnet. You can also use a hard object to scrape the surface plating layer. The brass surface (gold) on the surface of the copper button. The iron buckle is black, which is the color of the raw material.
How to determine if it is an alloy button?
The alloy buckle is relatively heavy and is die-cast. All mold lines are generally polished and polished. It may not be visible, but its weight is solid and solid.