Glass article and method of producing glass article

A method of producing a glass article comprising:

• holding a carrier having a circular shape, in which a glass substrate having a circular shape is retained, with an upper surface plate and a lower surface plate;
• and
• polishing the glass substrate by rotating the carrier with respect to the upper surface plate and the lower surface plate, to obtain the glass article, wherein:
• the glass substrate is disposed in the carrier such that, in a top plan view,
• a center Oc of the carrier is included in a region of the glass substrate, and
• a center Og of the glass substrate is shifted from the center Oc of the carrier,
• wherein the glass article comprises a first surface having a circular shape wherein:
• a radius R of the glass article is within a range of from 50 mm to 150 mm inclusive,
• when, in the glass article, to is a thickness at the center Og, a first end is one end portion, t1 is a thickness at the first end, tx′ is a thickness at any position X, except the first end and the center Og, between the first end and the center Og, and
• a thickness is measured from a first-surface side of the glass article by an optical interferometry type thickness measurement method, conditions of
• 0.1 mm<to<2 mm expression (1),
• 1<to/t1≤1.1 expression (2),
• to>tx′>t1 expression (3), and
• txn≥(to−t1)×(n/5)+t1 expression (4)
• are satisfied, where n is any integer from 1 to 5, and txn represents a thickness at a position Xn of R×(n/5) from the first end toward the center Og, and wherein
• when a second end is an end portion opposite to the first end with respect to the center Og, t2 is a thickness at the second end, tx” is a thickness at any position W, except the second end and the center Og, between the second end and the center Og, and
• a thickness is measured from a first-surface side of the glass article by the optical interferometry type thickness measurement method, conditions of
• 1<to/t2≤1.1 expression (5),
• to>tx″>t2 expression (6), and
• twn≥(to−t2)×(n/5)+t2 expression (7)
• are satisfied, where n is any integer from 1 to 5, and twn represents a thickness at a position Wn of R×(n/5) from the second end toward the center Og,
• wherein:
• the glass article has a thickness that monotonically decreases from the center Og toward each of the end portions,
• the glass article comprises glass having a refractive index of 1.6 or more, and
• the glass article comprises glass having a surface roughness of 0.5 nm or less.