Book VI, chapters 8–13: Counterfeiting precious stones

CHAP. VIII.

Of making smalt or Ennamel.

AFter Gems we will endevour to make Smalt or Ennamel. It is a work almost of the same nature, and of the same mixture and colours; this onely difference is between them, that in Gems the glass is transparent, in this it is more dense and solid. In antient times they made their Checker or Mosaique work of it: and Gold-smiths do use it in colouring and enammeling gold. It is Tinne that gives it a body and solidity.

To make white Enammel,

Take two ounces of Lead ashes, four of Tinne; and make it into a body, with double the quantity of glass: role it into round balls, and set it on a gentle fire all night: take heed it stick not to the sides of the pot, but stir it about with an iron spattle, and when it is melted, increase the fire, and the business is done.

To make black Smalt.

To a pound of glass, you must adde a drachm of Manganess, for so it will be of the colour of a Lyon: then adde a drachm of Zaphara, and the mixture will turn black: make often tryal, if it be of a dark purple or violet-colour: for the Tin that giveth it the body, will make it blacker.

To make Smalt of a deep yellow.

You may put to every pound of Crystal a little Crocus Martis, and three ounces of Jalloline, as they call it, which engravers use: at last, Lead and Tin. But if you desire

To make Smalt of a paler yellow,

Instead of Jalloline, adde Jaletto, and you will have your desire.

To make green Smalt,

Adde burned Copper, and so it will be of a deeper colour: but if you desire it a paler, adde the flakes of Copper, which flie off, while the smith hammereth it, being red hot.

To make red Smalt,

Adde the rust of iron, very finely beaten: but when you would make

Smalt dark on one side, and transparent on the other,

Make your Pastils of earth, and double as much glass; set it a whole night in the fire of reverberation, and let it melt in a convenient vessel, stirring it with an iron rod: so you shall perceive both transparent and opacous parts in the same little Orb. So

To make Smalt of the colour of an Amethist.

It is done with nothing but Manganess: and if you would have it of a deeper colour, adde more of the body, that is, of the flower of Lead and Tin.

To make Smalt of skie-colour.

It may be effected with Zaphara, by adding somewhat more of the body.

To make speckled Smalt,

which being full of small specks, shall seem to be compounded of a great many lice, very pleasant to behold. The opacous Smalt being made, pour it upon marble, and then presently sprinkle some Crocus upon it, or drop some pale colour in specks, all over it, and you shall have your desire.

To make Smalt of two colours,

cast Smalt first of one colour upon a marble, as before; and presently after, some of another colour upon that: then with an iron rod press them close, and joyn them together.

To make the best kind of Smalt,

such as Goldsmiths use; to every pot allow two roles of Sal Soda, and some sand, of which glass is made, and it will be much more perfect.

CHAP. IX.

To make Smalt of a clear rose-colour.

THe most skilful glass-makers do labour very much, in colouring Smalt of a rose-colour; which is commonly called Rossiclere: seeing that in former times they did it most beautifully and artificially. I will set down what both I my self have dore in it, and what I have received from other friends: I have performed the best I could, to shew others an opportune way of making better. The manner is this: cast ten pounds of Crystal in a pot, and when you know it to be well melted, adde a pound of the best red lead, by half at a time, stirring it with an iron rod as fast as you can, for the weight of it will make it sink to the bottom: when it is well mixed, take it out of the pot with iron instruments fit for the purpose, and cast it into water: do this thrice: then mix with it five ounces of Tin calcined, and Cinnabaris of a most bright colour; and so stirring them about for three hours, let them stand a while. When this is done, adde moreover three ounces of vitrified Tin, and beat them together without any intermission, and you will see a most lively rose-colour in the glass, which you may use in enamelling Gold.

To make Glass of Tin.

Set a pound of Tinne in a strong earthen pot, into the fire: let it heat and melt; then remove it with iron tongs into the hottest flames of the glass-makers fornace, for three or four days. Afterwards, the pot being taken out, and cold; break it, and in the top you will find glass of a saffron colour, not clear: but the longer it standeth in the fire, the perfecter it will grow; neither have I known better in this kind, of those many that I have tryed. It must be reduced into fine powder: for the which not onely a morter and mills will be requite, but also a Porphyrian stone. If it be too florid, you may make it of a more faint colour, by adding glass to it.

Another way to make it.

This is onely for friends: Take nine parts of burnt Tinne, seven of Lead, two of Cinnabaris; of Spanish-soder and Tartar, one part and a half; of the Blood-stone one part, of Painters red a fourth part. And do with it, as in the former.

CHAP. X.

Of leaves of Metal to be put under Gems.

THere are certain leaves of Metal laid under Gems, which being perspicuous, are thereby made paler or deeper, as you will: for if you would have them of a fainter colour, you must put under them leaves of a more clear brightness: if of a deeper, leaves of a darker hue. Moreover, Gems being transparent, are seen quite through, and discover the bottom of the ring; which taketh much of their beauty off. This is an invention of later times, who by terminating the transparency of stones, with leaves of a most bright and pleasant colour, do fit and make up, and mend the colour of the stones. I have been very much delighted in this kind of work, and therefore will deliver it particularly. The leaves are to be made either of Copper alone, or of Copper, Gold, and Silver, mixt together. I will speak of those which are made of Copper alone: You must buy at the Brasiers-shops some thin plates of Copper, of the thickness of strong paper, that they may be the easier made thinner, which you must cut into pieces of three fingers in length, and two in breadth; so that a sheet of two pound, will be divided into a hundred and thirty parts: these we must divide again into two parts, that they may be hammered more easily: Take fourty and heat them, as Artificers do gold, when they beat it out into thinne rays. Let the anvile and hammer be smooth and polished, lest the heavy stroaks should make dents in the Copper, and break it. Discontinue your work by turns, so that you may hammer the Copper while it is hot, and prepared by the fire; and put it into the fire, when it is cold: for if you do otherwise, it will break in pieces; which you must presently remove from the rest; for those that are broken, will break others. But that they may be the more easier prepared, when they begin to be ex[…]eruated, I make use of this invention. There must be prepared two plates of iron, of a hand square, and the thickness of paper. Double one of them, that it may receive the other within the folds of it: so that they may receive the plates of Copper in the middle, and enclose them on all sides, that they can neither slip out, nor any dust or ashes fall in, so stick to them. When you have thus enclosed the Copper plates, put them into the fire, and heat them; then take them out with iron tongs, and shaking off the ashes, beat them with your hammer till they are cold, and so they will become thin and fine rays. But while you are beating one, set others to heat: and do this eight times over, until you have hammer'd them very thin, and made them fit for your purpose. It will be worth your labor to look often upon them, to see if any be broken in the working, for they will break their fellows. But because they are wont to grow black in the working, and foul, so that they oftentimes deceive the eye; therefore it is fit, that you have a pot of water ready, with an equal quantity of Tartar, and salt in it, and let it boil over the fire: Put into it your rays, and stirre them about continually, till they be boiled white. Then take them out, and wash them in a pot of clear water, till they be very clean: then dry them with a linnen cloth, and then heat them, and beat them on the anvile again, as before, until they spread into rays, as thin as leaf-gold, When this work is to be done, the hammer and anvile must be as smooth, and polished, and bright, as a looking-glass; which you may effect in this manner. First of all, hold them to the grinde-stone, wherewith they grinde knives, until they be smoothed and planed, then rub them with fine sand, and Pumice-stone; afterwards glaze them with a wheele, and polish them with a plate of lead, and powder of emerald: if you use any other art, you will but lose your labour. Thus in two days your work will be finished, that is, by heating your plates, eight or ten times, and preparing them, and by whiting them four times at least: Finally, examine them all, whether they be whole, and of a sufficient thinness: so that if any remain too thick, they may again be brought to the hammer and perfected. But I must advertise you, that the thinner they grow, the less time they must lye in the fire, because they will presently melt: and so also in the water, because the salt will eat into them. At last, cut them with sheares into square pieces, that they may be more convenient for use.

CHAP. XI.

How leaves of Metals are to be polished.

THe plates being thus thinned and finished, we will fall to polishing of them. But first we must provide tools, wherewith to perform it. Take a plate of Copper of a foot in length, and a hand in breadth, most exquisitely burnished, that it may be as smooth as a looking-glass: bow it either with your hand, or a hammer, by little and little, into the form of a semicylinder. Then turn a piece of wood, so that it may be equal, and fit for it in every part, and be received into the convexity of it, where being fastned with four nails at the corners of the plate, it may remain stedfast. Fix this wood upon a little frame, with two bars of a foot height, fastned to the ends of it. Now we will begin to burnish the plates; which must be thus done: provide chalk made into fine powder, after this sort; take some beaten clay, wrap it in a clean and indifferently fine cloth, and put it into a washing-bowl full of water; stirre it about here and there, in the water, that the finest part may be washed through, and the courser remain in the cloth: then put the new chalk into the cloth again; stirre it and strain it till it all pass through the cloth, and then suffer the water to settle, and seirce it through a strainer; onely changing the water, until no gross settlement remain: Then lay the cloth over the mouth of the vessel, which must receive it, and tie it slack on: so strain it, that you may be the more sure, that nothing but what is very fine can pass through: then press cut the water, and reserve the chalk. Lay this clay, thus prepared, upon the Copper, and rub it with a poplar stick, till it shine like gold: then wash it with water, over a wide-mouthed pan, that may receive the water. After this, have a blood-stone ready, very well polished, upon a plate of lead, with the dust of Emerald, it will become most exquisitely smooth: therefore, lay your rays of copper upon the copper, and spread it abroad with the thumb of your left hand; then cast on the clay, and pour water on to wash it, and then wipe it off, and let onely the water remain to fasten them upon the copper. Then take into your hands the stone, being fastened to a stick; and polish the plates with it, having a great care that they do not run into wrinkles; for then they are quite spoiled: but when they begin to move, pour on some of the water, and that will fix them again: Continue this, till you have made it all over as bright and smooth as a looking-glass. A token of their perfect polishing is, when no marks of the running of the stone, is seen upon them. Then taking them off from the wood, cast them into a pot of water, until the rest are all finished; and then wrap them in a clean linnen cloth: dry them, and lay them up in boxes, free from all dust, and filth: but bend them like a half-pillar, so that the polished side may be inward; and tie them so with a string.

CHAP. XII.

Of building a fornace for the colouring Plates.

NOw we will shew how to colour them: but first, let us describe the fornace, wherewith it must be done. Therefore let a Fornace be made of iron plates of a convenient thickness: let it be a foot in height, and as much in the diameter of the length; let it be covered on the top, with a circular plate: In the centre of the roof of it, cut a round hole, a handful in breadth; and set another fornace upon it, of the same length and breadth, and make a hole in that also, which must be set against the other, and joyn them close together. Make a little door in the lower fornace, close to the ground; let it be made with an arch, four fingers wide, and jet out half a foot, like the mouth of an oven, and be joyned in the same manner to the great fornace. Then kindle your coals in another place, until they cease moking, and with iron tongs cast them into the foresaid fornace: Heat it very well, and let the outward fornace or mouth of the oven be fill half way with live coals. These being thus disposed, fall to colouring the plates. And first, I will teach you

How to colour plates with a purple colour.

Take the plates tyed about with thread, as I told you, and fit them upon a pair of iron tongs, which you must fasten at the fore-end with an iron ring, that they may not open: hold them upon the hole of the upper fornace, that they may receive the ascending smoak; and turn them about, until by degrees you shall perceive them gather a purple colour, without any other smoak then what ariseth from the heat of the coals: when you think them coloured enough, remove them from the smoke, and lay them aside.

How to make them of a Saphire colour.

It is done much after the same way: for taking the rays in an iron tongs, and holding them over the hole of the fornace, cast upon the coals through the low arched door, the feathers of a goose, which grow upon her brest, and then lay upon them a red hot iron rod. For the smoke of the feathers, arising through the tunnell of the fornace, will beat upon the rays, and make them of a sky-colour: when the iron rod groweth cold, take another and put in. It is very admirable, how on a suddain these copper rays will change into several colours: wherefore, when they have obtained the colour which you desire, take them off the fornace presently, for otherwise they will alter into another.

How to make them of a silver colour.

Take a little silver, and dissolve it with aqua fortis: then pour some fountain-water into it, and your copper rays: presently the water will be troubled, and will stick upon the copper like silver fleeces: cast away the water, and wash the silver, and dry it in the Sun; and when it is dry, lay it upon a marble, and mix with it an ounce of Tartar, and as much ordinary salt; grinde them together, till they be well mixed. This being made into powder, lay it on copper, and rub it with your fingers, and it will make it shine like silver: then spread the rays upon the round wood, and the copper; wet them with the water, lay the powder on them, and rub them with your thumbs, that they may become of a silver colour; steep them in water, and levigate them with the blood-stone upon the foresaid copper; then set them in the smoke, and they will shine with a sky-colour.

How to make them of the colour of an Emerald.

It is very difficult, and there scarce is one of very many that will prove right. First, make your rays of a sky-colour, as before; then take those which have not took that colour rightly, and lay two of them upon the hole of the fornace; and through the vault of the little door, fling some leaves of Box upon red hot plates of iron, where they will crackle like day-leaves, and send up a smoke through the hole, which will colour the rays. But before they come to be of a green colour, they must pass through many other colours, as yellow, red, and sky-colour; but they must continue some time before they obtain a perfect green.

How to make them red, like a Ruby.

Fling some flocks of Scarlet upon the live coles, and lay the thin plates over the hole, and the arising smoke will colour them red.

How to make them of the colour of the Amethist.

When it is made of a sky-colour, it passeth through the colour of the Amethist; take it therefore off in time, and you have your wish.

CHAP. XIII.

How rays are to be coloured by a mixture of Metals.

I will now shew how rays may be coloured by mixture with other metals; which is of more difficulty, but of longer continuance. The former cost but little labour, but they easily lose their colour: these are harder to be made; but keep their colour longer. Take half a pound of copper, and melt it in a melting pot, put thereunto half a crown of gold; and when it is well melted, and mixed, adde some tartar, that when it cooleth, the top of it may be plain and smooth; after it is cold, set it aside. Then take another half pound of copper, and melt it in the same manner; mix a drachm of silver with it, and let it cool: take it out of the pot, and file the out-side of it smooth; for the least crack, or chap, would spoil the work. You may know whether there be any crack within side or without, by this sign; place it in an even poise upon a piece of iron, and strike it with another piece; if it sound equally, and ring clearly, it is whole; if it do jar, it is cracked somewhere. Let your pieces of metal be about a finger in bigness; beat them gently upon the anvile, lest they break somewhere: set them in the fire and season them, and when they are cold, beat them with the hammer into thin rays, as I have said before: if they chance to crack, file off the flaws; and when they have been seasoned twice or thrice, in the fire, have your pot of water ready, prepared with salt and tartar, to whiten them, that you may more exactly find out the craks.

To make them of the colour of a Ruby.

The plates being finished, if you would make them of a ruby colour, do it with flocks of scarlet, as before; but then the rags must be of the mixture of copper and gold.

To make them of the colour of a Saphire or Emerald.

Let the plates be of copper and silver: the Saphire colour is made with goose feathers, but the Emerald with box-leaves, holding them somewhat longer over the fire. And these are the experiments which I have made concerning Gems.