Tea Identification Please

I was given some tea by a friend over Christmas. It came in a lovely fancy bamboo box and it is labeled Tie Guan Yin top grade. The leaves are not rolled tightly, if at all, possibly indicating that the tea might be from a period when the rolling method was different; also, maybe the leaves have unrolled somewhat over time. The tea is dark in complexion, so it clearly must be aged, I would have thought: intentionally or unintentionally, I’m not sure, however. The tea was bought in Hong Kong. It was a certainly, originally, a good quality tea, I would presume, in that the general taste and aroma is very rich and complex; however, the main characteristic of the tea is that has a very distinctive peat aroma and flavour. I’ve never tasted anything like it before, and I was wondering if anyone could help me find something similar. Could it be that the tea was over roasted and I’m enjoying a tea that is spoiled? Even if this tea has not been processed correctly, I enjoy it very much. The problem is that I don’t know where I’d find something similar. Thank you for your help, in advance.