The disclosure relates to methods of forming a vessel and to the resulting vessel. The vessel may be formed by providing a first fumed silica soot layer comprised of primary particles of fumed silica soot, and then providing over the first fumed silica soot layer a second fumed silica soot layer comprised of agglomerated particles formed into an agglomerated form from primary particles of fumed silica soot. The primary particles of the first fumed silica soot layer may have a substantially uniform density distribution, and the agglomerated particles of the second fumed silica soot layer may have a substantially non-uniform density distribution. The methods may include consolidating the first and second soot layers together to form a consolidated body.