my life is mine and mine alone
the crowns are made to match the color of your teeth

spongebobrogers
The minimum standard for high noble is at least 40% gold and a total of at least 60% gold plus other "noble" metals, such as platinum or palladium, which usually sell for more than gold. A noble crown is still gold but less amounts and with cheaper added metals, which can make the crown softer and not last quite as long also can contribute to allergies if you are prone to metal allergies. In general, most people wouldn't ever notice the difference.