un anillo de diamantes

a diamond ring

→ uno
phrase Rare #44,288
a diamond ring The singular form is un anillo de diamante. The plural form un anillo de diamantes is also very common.
SP: Ella recibió un anillo de diamantes por su cumpleaños.
EN: She received a diamond ring for her birthday.

Si fuera un rico, te compraría un anillo de diamantes.

If I were rich, I would buy you a diamond ring.

Dijo que era tacaño porque no le compré un anillo de diamantes.

He said I was stingy because I didn't buy him a diamond ring.

— Malcolm X (1992)

Es un anillo de diamantes.

It’s a diamond ring.

Tom no le dijo a nadie que había comprado un anillo de diamantes para Mary.

Tom didn't tell anyone that he had bought Mary a diamond ring.