What's the Name of That Book??? discussion

The author's name I have deduced is after the name Warner. I read this book when I was about 10 in my middle school library. It's my favorite book and I think about it nearly everyday. Can't remember the title, author, or cover. I do remember the plot and which shelf it sat upon in the old library a decade and a half ago. It had to be young adult or adult fiction. I read it in between the Boxcar Children series and Othello.

Plot: (Some of my memories are a bit hazy so bear with me please. I'll label the details I'm not sure of with 'may'.) The book begins with a girl who is deep within a mine. She may have been in an old abandoned shaft and she is curled in a narrow corridor. She feels safe and warm and like the mountain speaks to her. I don't remember the name of the characters (I'm bad at remembering names in general.) She is apart of a class of people who are branded upon the forehead and classified as slaves. They mine a material that may be used as a power source in this world. The girl has a mother. One day a man who may be black skinned comes to their village. He is searching for one who has the rare ability as he to sense the material. He discovers that the girl has this ability and his entourage is scandalized that he picks this sub class human. But the man is kind and understanding. They take her away from her people to go into training. The mother runs after the cart and it is an emotional departure for the girl. The man becomes her teacher and begins to take her to what may be the capital of this world. But, tragically, along the way the man disappears in a snow storm and is assumed to have died. The girl continues on alone. She eventually reaches the capital and she is taken captive at what may be a palace. She marvels at the ornate and enormous doors of the building. The men there who may be priests scorn her and do not believe that she is the one who was chosen by the man who so recently died. But she pleads with them and demands that they test her ability. They agree to a test which is held the following day. She is led to a field out front of the palace which has been strip mined of the material. She lays her head on the ground to feel for the material but knows that what was once here was mined long ago. She is followed by a group of priests several hundred in number. She walks up to them and claims defeat, that the material is not in this place. They sneer at her. But as she walks through the group she stops in front of one young man and says that he has the material in his possession. He pulls out a small stone of it and then all the other priests pull out a fake of the same sized and colored stone. She ends up proving herself in the end.

Winter of Fire by Sherryl Jordan?
"...tale set in an ecologically devastated future. Living in treeless mountains under cold perpetual clouds, human society has split into two classes: the autocratic Chosen and the despised Quelled, who mine the coal that's the only available source of heat. To general consternation, the ruling Firelord has picked Elsha, an angry Quelled teenager, as his new and only Handmaid; she vows to better the lot of her people, though it means battling centuries of prejudice"

Lisa, if that's not it, what year did you read your book?

That does sound like it. The cover looks familiar in my hazy memory too. You're amazing! Thank you so much. I'm going to go and look this up at my library. I'm going to count this as solved.

Great! Just come back if this doesn't turn out to be your book.