I managed to isolate some white (yellow) P4 from 12g (NaPO3)6, 5.4g Al powder and 3.6g SiO2 silica sand. I heated the mixture to 1000 C for half an
hour in a stainless steel retort. During the process sometimes P4 vapors (or P2H4 gas) made small explosions in the receiver, but can also be liquid
P4 over 100 C hitting water. Anyway I used the safety precautions, using leather welding gloves, an apron and a face shield and keeping safe distance,
because P4 is very nasty stuff.
Then I shutdown the furnace, let it cool and let the glass jar with water and P4 in it settle down and found small quantities in yellowish color.
After a day I fished one small piece out of the jar and ignited it.