These crystals are resin from a tree found in the East Indies. It is used for hardening beeswax by raising its melting temperature when used in encaustic applications.
To make your own encaustic medium: because the damar is in its raw state (it comes from the tree), it must be melted with the beeswax and strained to remove impurities.
Use in a well-ventilated area. Melting point: 212-302°F/100-150°C.