A near-infrared cut filter glass includes: P, Al, R (R represents any one or more of Li, Na, and K), R (R represents any one or more of Mg, Ca, Sr, Ba, and Zn), and Cu, and not including F practically, wherein (Cu.sup.+ amount/total Cu amount)100[%] is 0.01 to 7.0%. The filter glass may further include, by mol %, 0 to 10% B.sub.2O.sub.3. The filter glass may have a fracture toughness value of the near-infrared cut filter glass is 0.3 MPa.Math.m.sup.1/2 or more. For the filter glass, a quotient obtained by dividing an absorption constant at a wavelength of 430 nm by an absorption constant at a wavelength of 800 nm, of the near-infrared cut filter glass, may be 0.00001 to 0.19.

An organic-inorganic composite, including: a discontinuous phase having a plurality of adjacent and similarly oriented fibers of an inorganic material; and a continuous organic phase having a thermoplastic polymer, such that the continuous organic phase surrounds the plurality of adjacent and similarly oriented fibers of the inorganic material, and the organic-inorganic composite is a plurality of adjacent and similarly oriented fibers of inorganic material contained within a similarly oriented host fiber of the thermoplastic polymer. Also disclosed are methods of making and using the composite.

A lithium-ion conductive glass-ceramic article has a crystalline component characterized by the formula MA.sub.2(XO.sub.4).sub.3, where M represents one or more monovalent or divalent cations selected from Li, Na and Zn, A represents one or more trivalent, tetravalent or pentavalent cations selected from Al, Cr, Fe, Ga, Si, Ti, Ge, V and Nb, and X represents P cations which may be partially substituted by B cations.

A lithium-ion conductive glass-ceramic article has a crystalline component characterized by the formula MA.sub.2(XO.sub.4).sub.3, where M represents one or more monovalent or divalent cations selected from Li, Na and Zn, A represents one or more trivalent, tetravalent or pentavalent cations selected from Al, Cr, Fe, Ga, Si, Ti, Ge, V and Nb, and X represents P cations which may be partially substituted by B cations.

A phosphate-based glass fertilizer and a method for producing the same are provided. The glass fertilizer and a glass blend from which the glass fertilizer is obtained, have a composition that includes P.sub.2O.sub.5 with a molar proportion within the range between 40% and 50%, K.sub.2O with a molar proportion within the range between 8% and 17%, CaO with a molar proportion within the range between 15% and 25%, Al.sub.2O.sub.3 with a molar proportion within the range between 3% and 10%, and Na.sub.2O with a molar proportion within the range between 8% and 17%, with respect to the combined total molar amount of components that constitute the composition.

A phosphate-based glass fertilizer and a method for producing the same are provided. The glass fertilizer and a glass blend from which the glass fertilizer is obtained, have a composition that includes P.sub.2O.sub.5 with a molar proportion within the range between 40% and 50%, K.sub.2O with a molar proportion within the range between 8% and 17%, CaO with a molar proportion within the range between 15% and 25%, Al.sub.2O.sub.3 with a molar proportion within the range between 3% and 10%, and Na.sub.2O with a molar proportion within the range between 8% and 17%, with respect to the combined total molar amount of components that constitute the composition.

An optical component with improved degradation resistance is provided. The optical component includes an optical material and a coating. The optical material has a native surface that is susceptible to degradation processes. The coating is a layer of an inorganic material and is applied so as to be substantially contiguous so that there are no continuous paths between fluid surrounding the optical component and the optical material.

An optical component with improved degradation resistance is provided. The optical component includes an optical material and a coating. The optical material has a native surface that is susceptible to degradation processes. The coating is a layer of an inorganic material and is applied so as to be substantially contiguous so that there are no continuous paths between fluid surrounding the optical component and the optical material.

Provided is a near infrared absorbing glass excellent in each of weather resistance, resistance to denitrification, and optical properties even if not containing fluorine. A near infrared absorbing glass containing, in % by mass, 25 to 60% P.sub.2O.sub.5, 2 to 19% Al.sub.2O.sub.3, 10 to 45% RO (where R is at least one selected from Mg, Ca, Sr, and Ba), 0 to 13% ZnO, 12% to 20% (exclusive of 12% and 20%) K.sub.2O, 0 to 12% Na.sub.2O, and 0.3 to 20% CuO.

Provided is a near infrared absorbing glass excellent in each of weather resistance, resistance to denitrification, and optical properties even if not containing fluorine. A near infrared absorbing glass containing, in % by mass, 25 to 60% P.sub.2O.sub.5, 2 to 19% Al.sub.2O.sub.3, 10 to 45% RO (where R is at least one selected from Mg, Ca, Sr, and Ba), 0 to 13% ZnO, 12% to 20% (exclusive of 12% and 20%) K.sub.2O, 0 to 12% Na.sub.2O, and 0.3 to 20% CuO.