Here are some tips for cleaning various types of fire and fire places:
Remove any dust and soot with the brush attachment of your hover or use a soft brush. Clean with a proprietary brick / stone product such as Hot Spot Fireplace Cleaner. Don’t be tempted to use water as it will cause soot marks to be absorbed by the brick making staining worse. Apply a sealer such as Hot Spot brick and stone sealer to protect and repel stains.
Before cleaning, remove all rust using a wire brush or steel wool. Severe cases may need treated with a chemical rust remover used as per manufacturer’s instructions. Re-blacken cast iron grates using a black grate polish / paste. It may be repainted using BBQ or stove paint from B&Q.
Wash over the tiles with a warm solution of washing up liquid. If necessary try a fine paste cleaner such as Jiff cream cleaner using a damp sponge. Take care of hand painted tiles or those that have the pattern applied over the top of the glaze. You can also use HG remover, (Never apply a damp cloth to tiles while they are hot as they may crack.) When dry lightly polish and rub well with a soft duster.
For regular cleaning wipe with a solution washing up liquid and warm water. Polish once or twice a year with a proprietary marble polish to restore the shine, use plenty of elbow grease to get a good result. Avoid areas subjected to intense heat. Treat stains with HG Marble stain remover; this is a mixed to a paste and left to dry on the surface. For sever stains and chips you will need to call in a professional stone mason. Try the Stone Federation for one in your area.
Scrub with a stiff bristle brush dipped into a solution of washing up liquid and water. Once absolutely dry apply slate oil / dressing to enhance the colour. To remove scratches try rubbing lightly with a fine wet and dry sand paper, wash down, dry and then apply slate oil.