Highly dense brittle-material structural member having impregnating property

A non-sintered highly dense aggregate of brittle material particles having interfaces at which the particles are bonded to each other and pores between the brittle material particles,

• wherein a porosity which is a volume ratio of the pores with respect to the whole of the non-sintered highly dense aggregate is equal to or less than 20%,
• wherein a volume ratio of the pores communicating with an apparent outer surface of the non-sintered highly dense aggregate with respect to a volume of all of the pores of the non-sintered highly dense aggregate is equal to or higher than 65%,
• wherein the brittle material particles include first particles and second particles smaller than the first particles,
• wherein the second particles are located in a first gap between the first particles bonding to each other, and
• wherein the non-sintered aggregate has a second gap between the plurality of second particles located in the first gap and between the second particles and the first particles.