Drinking from a half gold bowl
In the name of Allah, the most Beneficent, the most Merciful
It is Makruh Tahrimi to drink a gold or silver cup/bowl. (Raddul Muhtar p.492 v.9)
The Prophet of Allah Sallallahu Alahi Wasalm has said ‘Do not drink from gold or silver utensils, do not eat in plates made from them, for they are for them (disbelievers) in this world and for us in the Hereafter’. (Sahih Bukhari p.841 v.2 & Sahih Muslim)
With regards to your question, if a bowl is half gold then the bowl will be considered gold, as ruling is given on the majority. Therefore, it will not be permissible to drink from such a bowl. (Fatawa Hindiyyah p.335 v.5)
Allah knows best.
Mohammed Tosir Miah
Darul Ifta Birmingham.