79 - To Make a More Graceful Emerald Paste
Take 2 oz of [rock] crystal ground as before, and 7 oz of ordinary minium. Mix them together well, as usual like the others. Add to them a proportion of 10 grains of verdigris per ounce. Therefore, to these 9 oz of material, there will be in all, 3 pwt and 18 grains of well ground verdigris. Also, add a a single dose of 10 grains of crocus martis made with vinegar
Blend these together with the minium and crystal, and put it into a crucible that is resistant to the fire. Lute it as before like the others, and then cook it as usual. Use it in small works because it will be loaded with colour.
Making it this way you will have a graceful emerald, very sightly, but not very hard due to the great amount of Iead. It is necessary, therefore, to let it cook in the fire more than usual, so that the fire consumes the lividness and unctuosity that by nature the lead confers, this produces a most sightly emerald.