Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What was Britain's (2013) birthstone when the U.S (2013) birthstone was ruby?

### Inputs:
table_name: table, columns: ['Month', '15th- 20th century', 'U.S. (1912)', 'U.S. (2013)', 'Britain (2013)', 'Hindu']

### Response:
SELECT Britain (2013) FROM table WHERE U.S. (2013) = ruby