Gray Stones In Slash'EM

Slash'EM has six types of gray stones: loadstones, flint stones, luckstones, healthstones, touchstones and whetstones. Loadstones, flint stones, luckstones and touchstones also exist in vanilla Nethack (see Dylan O'Donnell's spoiler on gems and luck for more information on luckstones). Healthstones and whetstones are new to Slash'EM.

As you might expect from the name, healthstones affect the rate at which you heal. Blessed or uncursed healthstones increase it, cursed healthstones decrease it, and unfortunately healthstones are always generated cursed. Unlike luckstones, healthstones are cumulative - two blessed healthstones are better than one. To be precise, you have a health bonus which is 2 for each blessed healthstone in you main inventory, plus 1 for each uncursed healthstone, minus 2 for each cursed healthstone. This bonus is added to your level and constitution when calculating how fast you heal.

A whetstone can be used to sharpen a metallic edged weapon i.e. to remove rust or enchant it up to +0 if it is negatively enchanted. However, this requires a source of water (a pool, fountain, sink or toilet), takes a long time, and only works 1/3 of the time even with a blessed whetstone.

How can we tell gray stones apart, other than identifying them? There are several ways.

First, kick any gray stone before picking it up. Loadstones are heavy, and unless you have strength 25, you'll just get a ``Thump!'' if you kick one. Make sure no monsters are in your line of fire when you kick the stone. Note that it is only cursed loadstones that stick to you; cursed healthstones or luckstones can be dropped or bagged without uncursing them first.
A cursed stone that isn't a loadstone must be a healthstone, unless it came from a bones pile.
Try applying an unidentified gray stone by rubbing a gem on it. If it is a blessed touchstone, it will be identified immediately, as will the gem. Otherwise, if it is not a touchstone, all gems and glass will make coloured scratch marks. If it is a touchstone, glass will leave colourless scratch marks and real gems will leave coloured streaks.
In shops, luckstones and healthstones cost 60 GP, touchstones and whetstones cost 45 GP, and flint stones and loadstones only cost 1 GP.
Zap a wand of enlightenment (a useful strategy for pseudo-identifying rings and amulets, too) and look for messages about extra/reduced luck or health.