Dictionarium polygraphicum. To make a granate colour in glass.

Dictionarium Polygraphicum:
Or, The Whole Body of Arts Regularly Digested.
Vol I.
London: Printed for C. Hitch and C. Davis in Pater-noster Row, and S. Austen in St. Paul's Church Yard. MDCCXXXV.
1735
To make a GRANATE colour in glass.
The beauty of this colour is to express the yellowish red of fire, when it is expos'd to the sun.

Take crystal frit, and of frit of Rochetta each an equal quantity, mix them well, and to fifty pounds of these materials add half a pound of manganese of Piedmont prepar’d, half an ounce of zaffer prepar'd; mix them well with the frits; then put them by little and little into an earthen pot made red hot in the furnace, because the glass is apt to rise and run over.

After four days, the glass being well ting'd and purified, you may work it; you may increase or diminish the colour as much as you please, which depends on the discretion of the operator, who puts in the powders which ought to be put in orderly, that the matter be not spoiled.



To make a GRANATE colour in glas of lead.

The vivacity of this colour appears no less in glass of lead than in crystal, if it be carefully made.

Take ten pounds of crystal frit, and eight pounds of calx of lead, and after having added an ounce and a half of manganese of Piedmont, and a quarter of an ounce of zaffer both prepar’d (as is taught under the articles MANGANESE and ZAFFER) put the whole into a pot, heated in the furnace; twelve hours after cast that melted matter into water, and take out the lead that remains behind in the pot.

Then put the matter again into the same pot, and let it stand ten hours to purify.

Then mix it well with the iron, and let the fæces precipitate; then see if the colour pleases you; then work it to what uses you please, and you’ll have a glass of lead of a fine Granate colour.


To make a paste for an oriental GRANATE.

The Granate is very like the carbuncle, for being both expos'd to the sun, they exhibit the colour of live burning coals, being between red and yellow, which is the true colour of fire.

There are several sorts of Granates, both oriental and occiden tal, some deeper, others paler; but the jewellers know how to make them appear, by setting them on silver foils.

The way to imitate them is as follows:

Take two ounces of natural crystal prepar'd, and six ounces of minium, with sixteen grains of manganese of Piedmont, and two grains of zaffer prepar'd; let the whole be pulveriz'd and well mixt together, and being put into a crucible, set them into the furnace with its cover well luted; there let them bake with the same precautions given as to the pastes for other gems, and you will have a very fine Granate as resplendent as the oriental.


A deeper oriental GRANATE.

This colour will not only be deeper, but also far fairer than the precedent.

To make it, take two ounces of natural crystal prepar'd, five ounces and a half of minium, to which add fifteen grains of manganese of Piedmont prepar’d; and having pulveriz'd it, mix the whole together, and proceed in baking this paste as directed for other pastes, only take notice, you must here leave more empty space in the crucible, because this matter rises more than the others, wherein care must be taken. Then will you have a deeper oriental Granate than the former, which you may polish, &c.


Another fairer GRANATE.

This paste will be yet much fairer than the precedent, if you take to two ounces of natural crystal calcin’d and prepar’d, six ounces of vermilion or minium in fine powder, thirty-five grains of manganese of Piedmont prepar'd, and four grains of prepar’d zoffer, which being well pulveriz'd, mix together in a crucible, leaving a greater empty space than in the other, by reason the matter rises more than in the others; then lute the cover well, let it dry, and put it in the furnace to bake, as is directed as to other artificial gems, observing the same circumstances noted on that subject, and you will have a very fine Granate, fairer than the rest.