DOI Page / Citation link:
https://doi.org/10.11588/diglit.634#0239
ai4 A Corollary os Coins,
Letter IV. &n& set down the Weight in a Piece of Paper ; then form the Piece of
»„yV™V« Lead to what fashion you think best and most advantageous to the Stone;
then re-weigh the Lead so formed, and letting down the Weight, you
may find what the Stone will lose in cutting. The Lead will weigh three
times as much as the Stone, which is a sure Rule; and commonly it losech
one third pare in cutting.
To make Diamonds clean; if you see a chick Table Diamond in a
Ring, a Jewel, or in a Colled sor a Jewel, you must first make it clean
either with a little Pumice-stone, or with a few hot Ames, or with a lit-
tle Oyl, and boii it, which will make it very clean.
Valuation os Diamonds.
There is a Rule acurately to be observed, which is this; A Stone of
one Garrack is worth 10 /.; to value z Carr. multiply per 2, which makes
4, and that 4, per 10, the Price of 1 Carr. which makes 40 /.: So sor
5 Carr. 3 times 3 is 9 Carr. and 9 times 10 /. is 90 /. This for even Car-
racks comes nearest the true Value ; but for 5 or £ of a Carr. although a
Stone of 2 Carr. be worth 40/. yet in this Rule and way of reckoning
( meaning i a 'Carr. so valued ) ic is valued at but 5 of a Carr. which is
50 /. and 5 of a Carr. but at i of yo s. although a single Stone, containing
a Grain , or 5 Carr. is worth 30 1. As for Example : You would know
what a Stone of 6 Grains is wortli; 6 Grains is 3 § Carr. ; times % is 9,
and? times yo s. is 22/. 101, which is the Value of the Stone of 6 Grains.
So of y Grains, y times y is 25, and 2y times 12 s. 6 4. is ly /. 12/. 64.
To make a Foil sor Diamonds.
A Foil to be ict under a thick Table Diamond, is to be made with
Black Ivory and Mastick, picked and made very clear, with a very little
Oyl of Mastick co incorporate them.
Black Ivory and Turpencine heated on the Fire is good, but the former
is better.
For a thin Table, Black Ivory scraped very fine is good ; or take a lit-
tle of the said Ivory with a little Oyl of Mastick, and dry the same; or
Ivory with a little Gum ; fair Water is also very good.
If you sell a thin Diamond that hath high Bisalls, then you may set it
upon full scraped Ivory, which graceth the Play of the Stone.
A Role Diamond that is very thick, it's good to set it close upon the
Ivory, and it will play very well; or Black Velvet is good under a thin
Table-Diamond, scraped as you do Lint.
The R V B r.
There are four sores of Oriental Rubies; that which is the hardest, the
best, and fairest Colour, if ic be very fair and cut Diamond-Cut, is no
!ess esteemed than a Diamond for the Weight, ( or of the same Weight),
but it is rare to see such an one.
The second sort of Ruby is White, Oriental, and Hard, which also is
of good esteem, if cut os a Diamond-Cut, but not of so high Price as
the perfect Red Ruby; but yet if it be in Perfection, .'tis very rare, be-
cause there are but few of this sort.
The third sort of Ruby is called a Spincll, which is softer than the for-
mer, and is nothing of like esteem, because not so hard, neither hath it
the
Letter IV. &n& set down the Weight in a Piece of Paper ; then form the Piece of
»„yV™V« Lead to what fashion you think best and most advantageous to the Stone;
then re-weigh the Lead so formed, and letting down the Weight, you
may find what the Stone will lose in cutting. The Lead will weigh three
times as much as the Stone, which is a sure Rule; and commonly it losech
one third pare in cutting.
To make Diamonds clean; if you see a chick Table Diamond in a
Ring, a Jewel, or in a Colled sor a Jewel, you must first make it clean
either with a little Pumice-stone, or with a few hot Ames, or with a lit-
tle Oyl, and boii it, which will make it very clean.
Valuation os Diamonds.
There is a Rule acurately to be observed, which is this; A Stone of
one Garrack is worth 10 /.; to value z Carr. multiply per 2, which makes
4, and that 4, per 10, the Price of 1 Carr. which makes 40 /.: So sor
5 Carr. 3 times 3 is 9 Carr. and 9 times 10 /. is 90 /. This for even Car-
racks comes nearest the true Value ; but for 5 or £ of a Carr. although a
Stone of 2 Carr. be worth 40/. yet in this Rule and way of reckoning
( meaning i a 'Carr. so valued ) ic is valued at but 5 of a Carr. which is
50 /. and 5 of a Carr. but at i of yo s. although a single Stone, containing
a Grain , or 5 Carr. is worth 30 1. As for Example : You would know
what a Stone of 6 Grains is wortli; 6 Grains is 3 § Carr. ; times % is 9,
and? times yo s. is 22/. 101, which is the Value of the Stone of 6 Grains.
So of y Grains, y times y is 25, and 2y times 12 s. 6 4. is ly /. 12/. 64.
To make a Foil sor Diamonds.
A Foil to be ict under a thick Table Diamond, is to be made with
Black Ivory and Mastick, picked and made very clear, with a very little
Oyl of Mastick co incorporate them.
Black Ivory and Turpencine heated on the Fire is good, but the former
is better.
For a thin Table, Black Ivory scraped very fine is good ; or take a lit-
tle of the said Ivory with a little Oyl of Mastick, and dry the same; or
Ivory with a little Gum ; fair Water is also very good.
If you sell a thin Diamond that hath high Bisalls, then you may set it
upon full scraped Ivory, which graceth the Play of the Stone.
A Role Diamond that is very thick, it's good to set it close upon the
Ivory, and it will play very well; or Black Velvet is good under a thin
Table-Diamond, scraped as you do Lint.
The R V B r.
There are four sores of Oriental Rubies; that which is the hardest, the
best, and fairest Colour, if ic be very fair and cut Diamond-Cut, is no
!ess esteemed than a Diamond for the Weight, ( or of the same Weight),
but it is rare to see such an one.
The second sort of Ruby is White, Oriental, and Hard, which also is
of good esteem, if cut os a Diamond-Cut, but not of so high Price as
the perfect Red Ruby; but yet if it be in Perfection, .'tis very rare, be-
cause there are but few of this sort.
The third sort of Ruby is called a Spincll, which is softer than the for-
mer, and is nothing of like esteem, because not so hard, neither hath it
the