Jensen's Powder is a rare and magical substance found deep under the earth of Museurth. Occasionally it is mined, but its extreme volatility makes it difficult, and thus expensive.
Jensen's Powder, at first glance, looks like ground salt. At a closer look however, one finds that the individual grains of the Powder are more angular, and that it is closer to translucent blue than white.
Jensen's Powder has a slight acrid scent, and feels slightly oily to the touch (not that many people actually touch Powder: it has a nasty habit of slashing up your fingers). It is normally transported in metal barrels or boxes that airtight and locked shut.
The taste of Jensen's Powder has been described (by those foolish enough to taste it) as "much like you would imagine old fish would taste like, if they'd been fed on a diet of liver and lemons for ten years."
Jensen's Powder has a number of interesting properties which make it worth mentioning.
First, Powder is explosive. Highly explosive. When struck by a sudden strong force, lit by flame, contacted by water, or contacted by magickal flux, the Powder explosively expands, setting fire and knocking down anything near.
Secondly, Powder is highly poisonous. In any significant dose (more than two or three grains), ingestion of the Powder is fatal. In small doses, purging and leeching has been known to help the victim somewhat, although severe sickness usually takes the victim for days. Unfortunately for would-be poisoners, but probably fortunate for the rest of us, Jensen's Powder is insoluable in most liquids.
Handling of Jensen's Powder is dangerous, and not just because it might explode. Each grain is razor-sharp, and if it touches your bare skin, it slices into it, and buries itself in the wound. If not removed immediately, effects similar to ingestion of the powder ensue. Thus, thick gloves are typically worn to protect the hands.
Jensen's Powder is a naturally occuring substance, found in mines near gold and silver. It is difficult to mine, however, since sudden shocks cause it to explode, as well as magickal flux, making even magickal removal from the ground nearly impossible. Thus, there is fortunes to be made for those brave (foolish?) enough to mine the stuff.
As a result of the difficulty of its acquisition, Jensen's Powder is extremely expensive. Prices anywhere from 500 to 1500 gold per pound are common, and these prices can only be found where the Jensen's Powder is actually sold. Typically, quantities greater than 5 or 10 pounds are simply not available.
Some cities outlaw the sale of Jensen's Powder.
The obvious use for Jensen's Powder would be to create the legendary cannons of the Al-Kazzyd army. As it turns out, this isn't a particularly useful use for the Powder, since it is difficult to forge a cannon which is strong enough to contain the explosion, and thus most reputable military strategists shun the use of the dangerous and unpredictable contraptions.
More clearly useful is the collapse of enemy fortifications. Judicious use of Powder around the base of nearly any structure without magickal protection is enough to bring it down.
Powder has never made a significant inroad into the poisoner's arsenal, partly due to its volatility, and partly due to the lack of flexibility of ingestion.
Probably people are thinking of new uses for the Powder even now. I'm sure the world will be surprised.
Jensen's Powder was first discovered by Sir Roderique Jensen of Amberkeep. He named it, introduced it to his king, and died three days later while experimenting with it further.
The world has never been the same since.