Long lasting links of love

Several separate silver circles joined together to make one,
A small, round and dark like night sky charm attached on,
Always locked up in a secret, hidden room,
Only taken out on the day of a special occasion,
A gift from a person I love,
As clear as a shiny reflection,
If I lost it, I would be destroyed,
It’s like my sister, but much more,
I hope you will stay with me forever and ever,
So I can pass you down to my daughter (that’s if I have one of course),
A valued inheritance for years to come.