Article including inorganic compound and method of manufacturing article including inorganic compound

An article comprising:

• a first part having a porous structure;
• a frame body having a density larger than that of the first part and surrounding the first part in a plane where the first part and the frame body are arranged;
• and
• a second part between the first part and the frame body,
• wherein each of the first part, the frame body, and the second part includes a common inorganic compound, and
• wherein the second part has at least one of a first structure, a second structure, or a third structure,
• wherein in the first structure, an average thickness of the second part in a direction perpendicular to the plane that is smaller than an average thickness of the first part in the direction perpendicular to the plane,
• wherein in the second structure, the second part includes a plurality of portions including the common inorganic compound, the plurality of portions are separated from each other, and each of plurality of portions connects the first part and the frame body, and
• wherein in the third structure, a porosity of the second part is larger than a porosity of the first part and smaller than a porosity of the frame body.