TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The organometaloxo oligomer comprises a metal comprising silicon, titanium, iron, aluminum, zirconium, niobium, yttrium, magnesium, manganese, cobalt, nickel, copper, vanadium, cerium, alkaline metals, alkaline earth metals, and/or rare earth metals, preferably polyalkoxysiloxane. The first catalyst is acid or base (preferred), which is organic base and/or inorganic base, preferably ammonia hydroxide. A molar ratio of water to polyalkoxysiloxane is 0.25-4. The polyalkoxysiloxane comprises 4-20 silicon-oxygen units. The synthetic particles: have a residual carbon content of less than or equal to 1 (preferably less than or equal to 0.5) wt.% or less than or equal to 100 parts per million (ppm), a surface area of 5-1300 (preferably 450-700) m2/g, and a metal impurity of less than or equal to 100 ( less than or equal to 3) parts per billion (ppb) for each metal element impurity. The synthetic particle size distribution (90%) is 1-1500 (preferably 75-500) mu m. A residual hydrocarbon content as determined by acetonitrile extraction and gas chromatography-mass spectrometry (GC-MS) analysis is less than or equal to 1000 (preferably less than or equal to 1) ppm; and are silica particles. The glass article has a hydroxyl concentration of less than or equal to 5 (preferably less than or equal to 1) ppm. The silica particles are derived from an alkoxy siloxane. The silica particle: has hydroxyl level of below 5 ppm when densified and vacuum sintered; has a surface area of greater than or equal to 900 (preferably greater than or equal to 300) m2/g, a metal impurity of less than or equal to 50 (preferably 1) ppb for each metal impurity element, and a carbon content before thermal treatment of less than 1000 (preferably less than 100) ppm; and provides the glass article with the hydroxyl concentration of less than or equal to 2 (preferably less than or equal to 1) ppm, when fused into the glass article. The porous metal oxide, metal hydroxide or carbonate particles has a surface area of 150-1200 m2/g and/or a metal impurity of less than or equal to 50 ppb for each metal impurity.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (a) comprises: (i) mixing a first solution comprising an organometaloxo oligomer with a second solution comprising water, surfactant and alcohol to form a first mixture; (ii) adding a phase enhancer to the first mixture to form a second mixture; (iii) adding a catalyst to the second mixture to form the metal particles; (iv) treating the particles from step (iii) with the aprotic solvent; and thermally treating the particles to calcine and/or densify the particles. The methods: further comprise heating the particles at 20-110 degrees C and stripping organic material from the particles under pressures of -13 to 0.5 psig with or without gas sparging before or after the step (iv), curing the particles before treating with the aprotic solvent, recycling the organic material that is collected by stripping, decanting, washing with or without additional purification, separating the organic material, and supplying the organic material back into a metal alkoxide generation or particle formation generation operation; and comprise heating the particles for a first period of time before the step (iv), and subsequently stripping organic material from the particles by adding water to the system and heating the particles to 20-110 degrees C sufficient to facilitate the removal of organic material from the particles, washing the particles with water, successive rinsing with the aprotic solvent, and densifying the particles with or without a calcining treatment. The step (b) comprises: rinsing the particles with the aprotic solvent to remove organic material from the particles, decanting the aprotic solvent carrying the organic material, and repeating the steps until the particles have a desired level of hydrocarbon material; and adding water and the aprotic solvent to the particles, and heating the particles to remove a majority of the residual organic material, a majority of the aprotic solvent and a portion of the water. The treating and heating steps are each performed two or more times until a desired residual hydrocarbon level is obtained. One or more of the solutions formed during the process are regularly decanted to remove surfactants and higher alcohols from the solution, subsequent to treating the particles with the aprotic solvent, or as part of the process. The step (b) is carried out at 20-110 degrees C using the aprotic solvent for two or more times. The curing step comprises aging the particles, heating the particles, or heating and aging the particles. The first solution is prepared by at least partially hydrolyzing a silicon alkoxide to form polyalkoxysiloxane. The first mixture is formed by combining the polyalkoxysiloxane with water, the first surfactant, the first alcohol and the second catalyst. The aprotic solvent is separated from the particles and recycled for a subsequent washing operation, subsequent to treatment of the metal oxide particles with the aprotic solvent. The synthetic particles are densified and sintered to a bubble free puck without an intermediate calcination step. Preferred Components: The aprotic solvent is: acetone, dimethyl ether, dichloromethane, tetrahydrofuran, dimethylformamide, acetonitrile, dimethyl sulfoxide, and/or ethyl acetate; and replaced with water. EXAMPLE - No suitable example given.