My N20 Ultra is the Mystic Black and yes it's glass and very mirror like. i.e a fingerprint magnet !
I see no silver or grey look just black however I'm sure others see differently.
Hope that helps @Pixmovi
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 2.5/ Android 10.