Stone beads (and pearls) traditionally have fairly small holes for their size. The reason for this is twofold: one is that it can be difficult to drill the hole without breaking the bead - it is technically more demanding and puts the price up; and the other reason is that these beads may sell (wholesale) by weight, so bigger holes mean a smaller profit margin for the original seller.
That said - sometimes you just want a bigger hole! To string on leather or cord or what have you!
Most of these do NOT have holes large enough for Euro-style charm bracelets (Pandora, Troll, et al.) Check the description for the size of the hole, and if unsure - just email us to have us check. (Euro-charm bracelets need a 4 mm or larger hole.)