Natural stone does not offer bullnose edged tiles like ceramics and porcelain tiles. Every edge that will be exposed that will require finishing requires sending it out for finishing prior to installation or finishing it on the job site, using grinders and buffers. We are entering the realm of old world craftsman here. This becomes much more art than science and experience definitely counts.
Natural stone will absorb water and chemicals, so all natural products require an additional step of sealing them. Some require a pre-grout release to be applied so that the grout itself will not stain the stone!
Natural stones require double the strength in the floors they are set on. This is not because of weight but because of stones lack of tolerance for floor deflection. There are exact formulas of deflection used in tile setting, stone requires exactly 1/2 the deflection in the underlayment below it. This can require additional costs to strengthen the floor before stone can be applied.
Some stones will warp and some will bleed through the setting materials used on them. Special setting materials are often required and extra care is needed to guaranty long lasting installations.