Chalk on a chalkboard is one of the worst feelings through my body but I guess it would be most limestone since chalk is made of it!
Chalk definitely creeps me out they should ban the sale and distribution of it.
Yes, especially since you rarely see the old style blackboards made of slate stone anymore.  It seems like colleges use the term blackboard for online stuff more then it is actually used.
Yeah it's not something that is used much with dry erase boards in most class rooms. Only old classrooms have it and I imagine they will be phased out.
Especially with how much technology is taking over and whiteboards being used as a writing pad and software application.
The sound of nails on a chalkboard is really the worst, but you know I might miss it. It can be very nostalgic.
Well you could always watch a YouTube video with it and future teachers can put that on for their students so they don't miss out either haha. It would integrate old school and technology and get students to understand more of the past!
Well either way they are going away and piece of history with it.
Social impact of YouTube
As the world's largest video hosting website, YouTube has had impact in many fields, with some individual YouTube videos having directly shaped world events.
YouTube enables inexpensive creation and distribution of academic educational content, as well as "how to" videos created by individual YouTubers. Worldwide video access has spurred innovation by enabling geographically distributed individuals to build upon each other's work and to collaborate. 
While YouTube videos have spread of awareness of social issues (such as bullying, suicide and LGBT issues
of wet blackboard can be difficult to remove. Blackboard manufacturers often advise that a new or newly resurfaced blackboard be completely covered using the side of a stick of chalk and then that chalk brushed off as normal to prepare it for use.
Chalk sticks.
Sticks of processed ‘chalk’ are produced especially for use with blackboards in white and also in various colours. White chalk sticks are made mainly from calcium carbonate derived from mineral chalk rock or limestone, while colored or pastel chalks are made from calcium sulfate in its