UV glass glues:
UV glue is suitable for clean new fractures. At least 1 side transparent glass, hardened by UV lamp. It has no filling effect, glues invisibly and is not suitable for outdoor applications and in wet areas. With UV glue, the viscosity is important (degree of fluidity)

Epoxy glass glues:
2-component glass glue (glue + hardener) suitable for old fractures, among other things. Epoxy has a filling effect, is not very flexible and is not always UV resistant. Suitable for outdoor applications and in damp areas.

Silgel:                                                                                                                                                                                                                            Curing by silicone + 2nd component, this is the glue for appliqué work. Silgel does not require oxygen to harden, is very flexible, has a filling effect, is moisture resistant and UV resistant.

Polymer:
The all-rounder…. Curing in the open air (oxygen), suitable for mosaic, spot bonding, has a filling effect, is moisture resistant and UV resistant. Polymer provides a very strong glue bond and is 'reasonably' crystal clear.

Bone Glue:
You can use this to make ice flower glass yourself (it doesn't smell good), there are various instructional videos on YouTube.