Definitely unusual. It's easy to recognise. Even on spectrogram, it has characteristic double line. It makes that I can sing and I cannot.
I have big voice range, but I usually use low pitch. It's neutral, nor feminine, neither masculine. My voice is deep, it comes from "deep throat". When I was a kid, I had very guttural voice. Now only sometimes, because I trained. I hate when I want to tell my neighbours good morning, but I tell ghhhhht mohhhringhhhh. When I see them far away, I hyperventilate to avoid it. Few years ago I used Benzydamine to make local anaesthetic in my pharynx. It was too expensive. But I'd probably use Benzydamine again before important conversation (f.e. to get a job).
Sometimes I sound like a drunk. Some people smoke and drink to get drunk voice like mine. I have it naturally.
Sometimes I sound like on the Valium.
It depends on my voice option, which is on/off - guttural or deep. I don't have influence on it.
My pitch is lower and lower - I have many recordings and f.e. 2 years ago I had higher pitch and I thought it's low. It was low, but now I have lower.
My voice is resistant to any mastering, probably of this double line.