Laval lab offers a complete line of Platinum Crucibles, Platinum Molds, Platinum Dishes and Platinum Tipped Tongs.
For borate / glass fusion, Platinum Crucibles and Platinum Casting Molds are usually made of Platinum / Gold alloy.
With the addition of gold, the Pt/Au alloy acquires beneficial non-wetting characteristics compared with the use of pure platinum. Molten glass will not adhere to the platinum/gold alloy, making it ideal for use with XRF (X-ray fluorescence) analysis, ICP & AA.
Click for more info :https://lavallab.com/all-products/platinum-crucibles-and-platinum-labware/