Endral / Forgotten Crystal

Endral, also known as Forgotten Crystal (Crystal of the Forgotten Lands) is a pink/red glass-like material. It is relatively fragile and it is very difficult to bind smaller pieces in to a larger whole, making large crystals of Endral particularly rare and expensive.
The largest known singular piece of Endral is The Fire Crystal.
When a spell is directed through Endral, the crystal match its internal arcane weave to match that of the spell and, if the crystal can draw enough energy, it will continue to emit the effects of the spell indefinitely. Obviously, some spells will work better than others - the simpler the spell, the closer the effect emitted from the crystal will match the original magic cast in to it.
Once Endral has been effected by a spell in this way, its arcane weave has been changed permanently and it cannot be used to cast a different spell.
To emit any magic, Endral needs to draw energy from somewhere. The most common energy source used in this manner is fire - setting an Endral shard above an open flame can make the crystal continuously emit a spell as long s the fire burns. Larger pieces of Endral, or at least pieces with a large surface area, can even use sunlight as an energy source - although finding a piece large enough to do this is rare.
The magnitude of the magic emitted from Endral also depends on the size of the crystal. Smaller shards will emit very weak versions of a spell, while larger pieces can produce much more powerful effects. An orb of about 3 inches in diameter is required to successfully emit a 1st level spell at full power, while you would need an orb double the size for a 2nd level spell. A 1st level spell cast into a crystal which is many meters wide would produce a much more powerful version of the original spell cast in to it.
Finally, casting magic in to a piece of Endral also draws magic from the caster themselves. This effect is negligible with smaller pieces, often going unnoticed by the caster. With larger crystals, however, this effect can be dangerous. If a crystal attempts to draw too much magic from the caster, the caster will suffer an effect known as Entrpoic Burn, rendering them unable the channel magic for a time. The duration of Entropic Burn depends on the spellcasters power and the size of the crystal and can last anywhere between a few minutes to many years. Some wizards have never been able to recover from these effects. In this case, the crystal will also be unaffected by the spell and will not change its arcane weave but will remain inert.
The Fire Crystal has never been activated due to its size.