Producing a molded body made of opaque quartz glass includes providing SiO.sub.2 grains obtained by comminuting quartz glass having a purity of at least 99.9 wt % SiO.sub.2, forming a slurry containing a suspension liquid and the SiO.sub.2 grains and which has a total solids content, wet grinding the SiO.sub.2 grains in the slurry so as to form ground SiO.sub.2 grain particles, forming a porous green body from the slurry, and sintering the porous green body. To provide a low cost quartz glass, the wet grinding of the SiO.sub.2 grains takes place at least temporarily in the presence of SiO.sub.2 nanoparticles, the proportion of which in the total solids content of the slurry is in the range of 0.1 wt % to 10 wt %, and the slurry has a solids content in the range of 76 to 80 wt % after addition of the SiO.sub.2 nanoparticles and after the wet grinding.

Methods for engineered mesoporous cellular magmatics and articles thereof are disclosed. For example, the magmatics may include a mixture of substance that, when exposed to heat for a length of time, form a foamed mass. The foamed mass may be exposed to a solution configured to cause mineralization upon and within the articles.

Methods for engineered mesoporous cellular magmatics and articles thereof are disclosed. For example, the magmatics may include a mixture of substance that, when exposed to heat for a length of time, form a foamed mass. The foamed mass may be exposed to a solution configured to cause mineralization upon and within the articles.

Methods for engineered mesoporous cellular magmatics and articles thereof are disclosed. For example, the magmatics may include a mixture of substance that, when exposed to heat for a length of time, form a foamed mass. The foamed mass may be exposed to a solution configured to cause mineralization upon and within the articles.

According to certain embodiments, a glass substrate comprises: a first portion; a second portion; and a third portion disposed between the first portion and the second portion, wherein the first portion, the second portion, and the third portion form a first layer having first ions, and a second layer having second ions; wherein an average thickness of the first portion is greater than an average thickness of the second portion, wherein an average of a depth of the first layer of the first portion is greater than an average of a depth of the first layer of the second portion, and wherein a depth of the first layer of the third portion gradually decreases from the average of the depth of the first layer of the first portion to the average of the depth of the second layer of the second portion.

A method for producing a blank of iron-doped silica glass with high silicic acid content for use as heat protection glass is provided. The method involves: (a) producing an iron-doped SiO.sub.2 soot body which contains iron in a first oxidation state Fe.sup.3+ by flame hydrolysis of a silicon-containing and an iron-containing starting substance, (b) drying the soot body to obtain a mean hydroxyl group content of less than 10 ppm by weight, and (c) vitrifying the soot body under a reducing atmosphere that is suitable for at least partially reducing the iron from the first oxidation state Fe.sup.3+ to a second, lower oxidation state Fe.sup.2+. A blank is obtained having an iron content between 0.1 and 1% by weight which exhibits an internal transmission of at most 40% in the infrared wavelength range and an internal transmission of at least 85% in the visible spectral range.