Lumenstone

Lumenstone is one of the world's most valuable- and widely used- items. A crystalline structure mined only in rare caves in Dwarven lands, treated extensively by alchemists with closely guarded secret compounds and processes, the material is one of the main exports and trade goods of those nations.
If exposed to open air the crystals emit a light that glows like a burning flame, but in a stead, even glow. Often small lanterns or containers will raise and lower the Lumenstone out of oil bath. When lowered, the crystal sits inert- but when exposed, light flows. More than simply producing light on demand, the crystals have another important property- they produce no heat as they glow, making them far safer than an open flame.
All Lumenstone produced by Dwarven alchemists is taxed heavily by the government ruling over the area, and as a way to sign that the stone has been properly accounted for a seal is burned into the base of the crystal. Naturally falsifying these seals is a constant business, as smugglers and bootleggers attempt to keep the black market for Lumenstone alive.

Properties

Material Characteristics

Lumenstone is a hard, vaguely yellow crystal with six to nine faces, with a blunted, squareish tip that has a vaguely pyramid-like point to it. As it ages, the yellow color dims and begins to be replaced with grey.

Physical & Chemical Properties

When not immersed in oil Lumenstone will emit a golden glow, not unlike that of a candle or flame. The larger the piece of Lumenstone (or surface area) the more light that is produced. Over time the crystal will decay and leave a dusty residue in the bottom of whatever container it resides in. The thinner the crystal is cut the faster it will decay, making crystals increase in value drastically by weight.

Geology & Geography

As far as is known, raw, unprocessed Lumenstone is only found in the Dwarven mountains, and in specific, rare caves deep underground.

Origin & Source

Lumenstone is "grown" from seed or base crystals found in deep caverns, massive translucent, milky-white crystal bases that can stretch up to two feet across, and grow smaller crystals off the exposed surfaces in spikes. If the basestone is cracked or harvested, the crystals will not regrow- but if a chamber with nothing but basestones is resealed and left for one or more years, small crystals will have reformed.

Life & Expiration

Depending on the area exposed, a thumb-sized crystal will take the better part of a month to decay if used nightly. Larger crystals with less surface area last longer, and powdered Lumenstone crystals would create a blinding flash that lasts a fraction of a second.

Odor

No notable smell

Taste

No notable taste.

Color

Crystalline yellow-white when pristine, cloudy grey-white when decayed.