Is Zakāh obligatory on all forms of Jewellery?

Zakāh is obligatory on all forms of gold and silver whether it is for personal use or otherwise. (Raddul Muhtār, 2:32) Once the Prophet (Peace be upon him) said to two women who had not offered Zakāh for their gold necklaces, “Do you not fear that Allāh will make you wear a bracelet of fire? Pay it’s Zakāh.” (Abū Dāwūd) However, there is no Zakāh on diamonds, rubies or pearls, unless they are for business purposes. (Durrul-Mukhtār, 2:273).