A gifting run that arrives damaged is worse than one that arrives late, and this is the most avoidable failure on this site.
What actually happens in the box
Coasters packed face to face are not static. Freight vibrates continuously for days, and two stone faces in contact grind against each other for the whole journey.
The edges go first, because that is where the contact pressure concentrates. By the time the box is opened, two or three in a set of six have small pale chips around the rim.
The fix
A divider between every piece — card or foam — so no face touches another face. That is the whole solution and it costs a few cents a set.
The outer box then has to be specified for freight rather than for presentation. Both is ideal; if you have to choose, choose the one that means the gift arrives.
Weight is a design decision
A boxed set of six granite coasters is a heavy parcel, and heavy parcels get handled worse, not better. Mixing a lighter stone into the set, or dropping from six to four, changes both the freight cost and the damage rate.
We will quote the shipping weight alongside the unit price so that trade-off is visible before you commit rather than after the invoice.
Test it before the run
Ask for one packed sample set and drop it from waist height onto a hard floor. It is a crude test and it tells you almost everything.
We would rather you did that with a sample than discover the answer across nine hundred client gifts.