Macro photography is a great challenge that takes patience and precision.
Some examples of magnifications are below.
This is an example of a shell and a US Quarter at 1:1 magnification on a full frame (35mm) sensor
This is an example of a shell and a US Quarter at 2:1 magnification on a full frame (35mm) sensor
This is an example of a shell and a US Quarter at 3:1 magnification on a full frame (35mm) sensor
This is an example of a shell and a US Quarter at 4:1 magnification on a full frame (35mm) sensor
This is an example of a shell and a US Quarter at 5:1 magnification on a full frame (35mm) sensor