The Scarlet "S"

The scarlet "S" stamped on the back,

Gives me joy to see in the mail,

With curves and swirls of the dark black pen,

They tint the envelope pale.

I carefully open, so as not to disturb,

The squished little ruby of red,

With it's bubbles and drips of crimson,

I have so many times over-read.

With a ruby on the outside,

What could it contain?

Other precious gems,

Of quality the same?