how to keep jaggery soft

Hi,

I get jaggery from the store but dont use it much in my daily cooking. However, when I use it (occasionally) each time, it gets hard like a rock, and is sometimes difficult to cut or grate it. Can you give me some useful tips to keep jaggery soft?

Thanks!

I use to keep in the microvave for some seconds before using, this will melt the jaggery.