IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL STONE
Year: 1885

page_text: I, JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF ARTIFICIAL STONE" which Invention has been communi-
cated to me from abroad by Ignaz Brandstätter of Vienna in the Empire of
Austria, Sculptor to be as follows:-
This Invention relates to the manufacture of a compact artificial stone of a sharp
or hard grain or texture and having the same qualities as natural stone, but being
superior to it in beauty and durability.
The artificial stone made according to this Invention may be employed for all
kinds of masonary for fronts of buildings for pavements for interior work and in
fact for all sorts of architectural and ornamental work and also for grinding and
sharpening purposes. It can be ground and polished and made in various colors.
In manufacturing artificial stone according to this Invention the following is the
proceeding-I take pure quartz and grind and sieve it in a dry state to a degree
in accordance with the grain to be given to the stone to be produced. Magnesia is
mixed with the material thus obtained. In general for every 100 parts by weight
of pure quartz 6 to 10 parts by weight of magnesia are employed.
If a higher degree of hardness be desired there is used instead of magnesia
about 4 to 6 parts by weight of minium or litharge which is thoroughly mixed
with the quartz and there is added to this mixture 12 to 16 parts by weight of a
concentrated solution of silicate of soda or potash which gives a nearly dry mass
which is then poured into moulds and submitted to a high pressure in a hydraulic
or other press.
The moulded stones are then taken out of the moulds dried in a close room and
finally burned at a white heat in any suitable oven or kiln. After burning the
stones are left for some time in the oven and carefully cooled.
In order to obtain an artificial stone for architectural and ornamental purposes
there are added to 100 parts by weight of reduced and sieved quartz 3 to 6 parts

page_text: by weight of magnesia or for a still higher degree of hardness instead of magnesia
there is employed 2 to 4 parts by weight of minium or litharge. These materials
being intimately mixed in a dry state 2 to 4 parts by weight of limestone or of
chalk or of marble in a fine powder are added and mixed thoroughly and then
there is added about 16 to 20 parts by weight of a concentrated solution of
Silicate of soda or potash until the mass becomes homogenous and plastic-It is
then poured into moulds and agitated until all spaces of the mould are uniformly
filled with the mass-The objects are then taken out of the moulds, well dried and
burned as hereinbefore described.
When it is desired to produce colored stones the desired colours must be added
to the materials before or after the addition of the solution of Silicate of Soda or
Potash,
The artificial stone thus made when used for constructions where no great
resistance or hardness is required will not require to be burned.

page_text: I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this invention which has been com-
municated to me from abroad by Ignaz Brandstätter of Vienna in the Empire of
Austria, Sculptor and in what manner the same is to be performed to be parti-
cularly described and ascertained in and by the following statement:-
This Invention relates to the manufacture of a compact artificial stone of sharp
or hard grain or texture from pure natural quartz and similar materials such as
flint or Silex, scraps of Granite and of quartzy slate Rock, and the siliciferous or
quartzy gravel of the sea, the said artificial stone having the same qualities as
natural stone, but being superior to it in beauty and durability and in consequence
of its homogeneity being capable of an easy cut and good polish.
The said artificial stone made according to this Invention may be employed for
all kinds of masonry for fronts of buildings pavements and for interior work and
in fact for all sorts of architectural and ornamental work and also for grinding and
sharpening purposes. It can be ground and polished and made in various colours.
In manufacturing artificial stone according to this Invention the following is the
proceeding Pure quartz or its equivalent as before stated is taken and ground and
sieved in a dry state to a degree in accordance with the grain to be given to the
stone to be produced. Magnesia is mixed with the material thus obtained. - In
general for every 100 parts by weight of quartz or the equivalent thereof 6 to
10 parts by weight of magnesia are employed.
If a higher degree of hardness be desired. There is used instead of magnesia
about
to 6 parts by weight of minium or litharge which is thoroughly mixed
with the quartz or the like and there is added to this mixture 12 to 16 parts by
weight of a concentrated solution of Silicate of Soda or potash which gives a nearly
dry mass. In either case the mass is then poured into moulds and submitted to a
high pressure in a hydraulic or other powerful press.
The moulded and compressed stones are then taken out of the moulds dried in a
closed room and may then be burned at a white heat in any suitable or well known
oven or kiln. After burning the stones are left for some time in the oven or kiln
in order to be carefully and gradually cooled.
For obtaining an artificial stone for architectural and ornamental purposes there
are added to 100 parts by weight of reduced and sieved quartz or the like 3 to
6 parts by weight of magnesia or for a still higher degree of hardness instead of
magnesia there are employed 2 to 4 parts by weight of minium or letharge. These
materials being intimately mixed in a dry state, 2 to 4 parts by weight of lime-
stone or of chalk or of marble in a fine powder are added and mixed thoroughly
and there is then added about 16 to 20 parts by weight of a concentrated solution
of silicate of Soda or potash until the mass becomes homogeneous and plastic.
It is then poured into moulds and agitated until all spaces of the mould are
uniformly filled with the mass.
The objects are then taken out of the moulds well dried and burned as herein-
before described.

page_text: When it is desired to produce colored stones the desired. colours must be added
to the materials before or after the addition of the solution of silicate of soda or
potash.
The artificial stone thus made when used for constructions where no great
resistance or hardness is required does not require to be burned.
Having now described and particularly ascertained the nature of this inven-
tion and the manner in which the same is to be performed I declare that what
I claim is
The manufacture of artificial stone from pure quartz (or the equivalent such as
Flint or silex or the quartzy or siliciferous gravel of the sea or scraps of granite or
Slate Rocks) and Magnesia or of quartz or the equivalent thereof and Minium or
litharge and a concentrated solution of Silicate of Soda or potash with or without
calcined or natural lime-stone or its equivalent in the proportions indicated or
thereabouts according to the purpose for which the stone is to be used the said
materials being moulded pressed dried and if necessary also burned substantially as
and for the purposes hereinbefore described also the artificial stone the produce of
the said process.