Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

A method of making articles from preformed materials includes placing a preformed material on a mold such that a non-quality region of the preformed material contacts the mold and a quality region of the preformed material is free of contact with the mold. A non-contact support is provided to the quality region to control sagging of the quality region. A reformable area of the preformed material is formed into a select shape by contacting the reformable area with a forming tool while restricting contact between the forming tool and the reformable area to the non-quality region. After the forming of the reformable area, an article is extracted from the quality region.

A method of making articles from preformed materials includes placing a preformed material on a mold such that a non-quality region of the preformed material contacts the mold and a quality region of the preformed material is free of contact with the mold. A non-contact support is provided to the quality region to control sagging of the quality region. A reformable area of the preformed material is formed into a select shape by contacting the reformable area with a forming tool while restricting contact between the forming tool and the reformable area to the non-quality region. After the forming of the reformable area, an article is extracted from the quality region.

A method for producing a glass article includes forming a glass sheet from a molten glass source and separating the glass article from the glass sheet. During the step of separating the glass article from the glass sheet, the water content of the atmosphere surrounding the glass sheet is controlled to be below a predetermined value. Such control of the water content of the atmosphere surrounding the glass article can effectively reduce the density of particles adhered thereto.

A method for producing a glass article includes forming a glass sheet from a molten glass source and separating the glass article from the glass sheet. During the step of separating the glass article from the glass sheet, the water content of the atmosphere surrounding the glass sheet is controlled to be below a predetermined value. Such control of the water content of the atmosphere surrounding the glass article can effectively reduce the density of particles adhered thereto.

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

Provided is a glass composition that exhibits greater Faraday effect than ever before. A glass composition contains 48% or more of Tb.sub.2O.sub.3 (exclusive of 48%) in % by mole.

A reforming mandrel and a method of use reforming mandrel to reform glass are described. The reforming mandrel comprises an upstream portion, a downstream portion and an at least partially hollow interior. The upstream portion may have an intake inlet for fluid flow. The downstream portion may be axially spaced from the upstream portion. The downstream portion may have a flattened cross-section defined by flattened peripheral portions joined by curved peripheral portions. At least one curved peripheral portion may be made of porous material resistant to a temperature of at least 1000 C. The at least partially hollow interior may communicate with the intake inlet and the porous material.

A reforming mandrel and a method of use reforming mandrel to reform glass are described. The reforming mandrel comprises an upstream portion, a downstream portion and an at least partially hollow interior. The upstream portion may have an intake inlet for fluid flow. The downstream portion may be axially spaced from the upstream portion. The downstream portion may have a flattened cross-section defined by flattened peripheral portions joined by curved peripheral portions. At least one curved peripheral portion may be made of porous material resistant to a temperature of at least 1000 C. The at least partially hollow interior may communicate with the intake inlet and the porous material.