what symbolizes 7th anniversary?

Answer 1

Anniversary symbols
Many anniversaries have special names. Generally speaking the longer the period, the more precious and/or durable the material associated with it.

1 year is a paper anniversary
2 years is a cotton anniversary
3 years is a leather anniversary
4 years is a linen anniversary
5 years is a wood anniversary
6 years is an iron anniversary

7 years is a wool anniversary

8 years is a bronze anniversary
9 years is a copper anniversary
10 years is a tin (or aluminium) anniversary
11 years is a steel anniversary
12 years is a silk anniversary
13 years is a lace anniversary
14 years is an ivory anniversary
15 years is a crystal anniversary
17 years is a turquoise anniversary
20 years is a china (porcelain) anniversary
25 years is a Silver Jubilee or silver wedding anniversary
30 years is a pearl anniversary
35 years is a coral (or jade) anniversary
40 years is a ruby anniversary
45 years is a sapphire anniversary
50 years is a Golden Jubilee - not to be confused with the 'golden birthday' (not at a fixed age)
55 years is an emerald anniversary
60 years is a Diamond Jubilee
65 years is a Blue Sapphire anniversary
70 years is a Platinum Jubilee.
75 years is a Diamond wedding anniversary
80 years is an Oak wedding anniversary

Answer 2

Easy! Wool.