Natural Stone

Granite

Commercially this includes all igneous rocks, plus gneiss and schist which are metamorphic but share similar properties and generally made up of the same minerals. Granites have great scratch resistance being around 6-7 mohs hardness. They are also etch resistant to common acids. However every granite has different levels of porosity some needing to be sealed regularly to avoid staining while others seldom.

Marble

A metamorphic rock made largely of calcite. Calcite can react with common acids causing surface etching on polished surfaces. It is also more prone to scratches being about 3 on the mohs hardness scale.

Dolomite marble contains more magnesium and less calcite making it less likely to etch and a bit harder to scratch at around 4 mohs hardness. Sealing all marbles periodically is recommended.

Quartzite

A metamorphic rock of fused sandstone. Quartzites are the hardest, most scratch resistant option available with a hardness of 7+ Mohs. They are also etch resistant to common acids, unlike marble.

Fully crystalized quartzites have very minimal porosity and require little sealing. Grainy intermediate quartzites however will require regular sealing.

Care/Maintenance

Whether a natural stone needs to be sealed regularly, or at all, will depend on the particular stone and its traits. Wash with warm water and mild dish soap, or a stone cleaner. Buff with dry rag. Avoid acidic cleaners with citrus, ammonia or bleach as these can etch the surface over long term use. Also avoid harsh cleaners with abrasives in them.

Engineered Quartz

(quartz)

Quartz

Stone made through a manufacturing process using ground quartz, resin and pigment. Engineered quartz is non-porous and requires no sealing, is etch resistant to common acids, and is about as hard as granite around 6-7 Mohs.

Care/Maintenance

Engineered quartz requires no sealing as its non porous. Wash with warm water and mild dish soap, or a quartz cleaner. Avoid acidic cleaners with citrus, ammonia or bleach as these can etch the surface over long term use. Acetone can be used briefly to get out tough pen/marker type stains but not recommended for regular use. Magic Erasers work well at removing scuff marks and metal marks. Bar Keepers friend work well also when used gently.