Yes, it’s true.
The natural sugars in honey form crystals that make it take on a solid form. Most of the honey sold in retail shops has added ingredients, or filtered-out ingredients to slow down crystallization and increase shelf appeal. For example, pollen that sticks to bees is abundant in pure honey, but is removed from most packed products because it contributes to a faster crystallization process.
With different flavors of honey, the natural sugar content varies. Some flavors begin to crystallize before others. Sunflower honey packs more natural sugars than other kinds of honey, and turns solid much faster. But don't worry, you can always submerge your honey jar in warm water for a few minutes.
So next time you see crystals in your honey remember: this only shows you’re getting REAL unprocessed honey!