46. Preparation of Lychnis.
Corrode
the stones beforehand as set forth above. In this manner take archil,
alkanet, and vinegar and place the stone therein as long as desired.
According to Pliny (Natural History XXXVII, 103) this stone was red in color like the ruby.
47. Preparation of Beryl.
Mix Indian black with resin and heat crystal. If you let it cool in the mixture then excellent beryl comes forth from it.
48. Another {Preparation).
Make
a solution from the bile of a tortoise together with the milk of a
pregnant animal, copper, and sharp vinegar; and in this solution beryl
will come into existence from stone. Only the experts can discover {the
fraud).
49. Preparation of Jasper.
Heat the stone, then corrode it in alum along with vinegar and put it in verdigris and calves' gall.
50. Preparation of Sunstone.
Boil
liquid pitch and alkanet, put the stone in it and it will thence become
sunstone; or in the juice of mulberries; or in ground kermes with
vinegar; or in A rmenian blue with calves' gall.
51. Corrosion of Crystal.
Before
one puts it in for coloring. Grind 1 part of quicklime and 1 part of
natural sulphur. Add vinegar and put the stones in it. And in the third
place it states thus; human excrement is, as they say, garlic.
This
latter sentence, which appears to have no connection with the remainder
of the recipe, is apparently a reference to some other work. It is of
value in showing the use of cryptic words and secret meanings.
52. Preparation of Sunstone.
Take equal parts of sulphur, vinegar, and calves' gall. First-class, flawless sunstone is turned out with this mixture.
53. Corroding and Opening Up of Stones.
Grind
alum and melt it carefully in vinegar. Put the stones therein, boil it
up, and leave them there over night. Rinse them off, however, on the
following day and color them as you wish by use of the recipes for
coloring.
54. Another {Recipe).
Put
the stones in a dish, lay another dish on it as a cover, lute the joint
with clay, and let the stones be roasted for a time under supervision.
Then remove the cover gradually and pour alum and vinegar upon the
stones. Then afterward color the stones with the dye as you wish.
55. Corrosion of Crystal.
Crystal, which undergoes uninterrupted corrosion a day and a night, becomes bluish.
56. Bleaching of Crystal.
Dissolve rice in water, put the crystal in, and again boil the solution with it.
57. Softening of Crystal.
Soften crystal by cooking in goat's blood. The same recipe also applies to glass.
