It is called a centenary. The word has a Latin origin: centum - meaning a hundred.
Bicentennial.
It is called silver or silver year.
A 100th year Anniversary is CAlled a Cenntenial .
A 100th year Anniversary is CAlled a Cenntenial .
A 300 year anniversary is called a tercentenary. A 400 year anniversary is called a quatercentenary. (be careful with the spelling of this one!)
A 10 year anniversary is called a decennial.
A 70th Anniversary is called a Platinum.
Quasquicentennial
A 70th Anniversary is called a Platinum.
An Emerald anniversary
Platinum year
150 USD or so
This would be your crystal anniversary.