Does pure honey Crystallise? 

This is good that your honey has crystallised. It means that it naturally contians high amounts of pollen and royal jelly.
All raw honey contain 22 amino acids, 27 minerals and 5,000 enzymes. Minerals include iron, zinc, potassium, calcium, phosphorous, magnesium and selenium. Vitamins found in honey include vitamin B6, thiamin, riboflavin, pantothenic acid and niacin.
Raw Honey also contains powerful superfoods, such as pollen, propolis and royal jelly.
It is normal for raw honey to crystallise at low room temperature (12C - 20 degree C). In fact, it is a sign of purity.
The more concentration of Pollen, Beeswax and Royal Jelly, the more quickly it crystallises.
It is only the filtered and heated honey that doesn't crystallise, however heat and filtration destroys the medical benefits of honey.
You may find more about Honey Crystallisation through a quick google search or press below:
honeypedia.info/why-does-honey...