See Unicode Technical Report #25

Size Circles Squares Diamonds Lozenges Triangles
Large ◯ / ⬤
25EF/2B24
⬛ / ⬜
2B1B/2B1C
Normal ● / ○
25CF/25CB
■ / □
25A0/25A1
◆ / ◇
25C6/25C7
⧫ / ◊
29EB/25CA
▲ /△
25B2/25B3 etc.
Medium ⚫ / ⚪
26AB/26AA
◻ / ◼
25FB/25FC
⬥ / ⬦
2B25/2B26
⬧ / ⬨
2B27/2B28
Med. Small ⦁ / ⚬
2981/26AC
◽ / ◾
25FD/25FE
🞙
1F799
🞟
1F79F
Small • / ◦
2022/25E6
▪ / ▫
25AA/25AB
⋄ / ⬩
22C4/2B29
⬪ / ⬫
2B2A/2B2B
▴ / ▵
25B4/25B5 etc.
Very Small ∙ / ∘
2219/2218
⬝ / ⬞
2B1D/2B1E
🞘
1F798
🞞
1F79E
Tiny
22C5
🞌
1F78C
🞗
1F797
🞝
1F79D

These are listed as something other than geometrical shapes:
00B7 is middle dot
2218, 2219 are math ring and bullet operators
22C4, 22C5 are math diamond and dot operator
2981 is a math "z-notation" spot operator