This vibrant yellow/green ‘Vaseline’ glass scent bottle gets its colour from uranium oxides. If exposed to ultra-violet light it will glow in the dark! However, there is no need to panic, as there are no safety risks from this type of glass because the radiation levels are the same as those that occur naturally in our environment. Coloured glass like this developed during the nineteenth century, with Bohemia (now the Czech republic) leading the way. Lighter coloured glass like what is used in this bottle is more sensitive to light damage making it more likely for the perfume inside the bottle to go off.