The Professor cleared the basic spells off the board, but left the one that Wolfe had written, just in case someone in the next seminar was dumb enough to try casting unknown magic.
What he replaced them with was far more detailed than Wolfe had expected. Instead of drawing diagrams on the chalkboard, he rolled down an overhead screen with a number of pages of diagrams attached to it.
"If you will all look at this first diagram, you will see the arrangement for a Fire Focus. This arrangement of gems can be used in most applications that require rapid heating or flame production. It is the core of most devices that enhance fire magic, as the positioning of the Gems around the spell sigil will increase its potency for a minimal cost.
Now, normally Sunstones are used, as they are cheap, abundant, and well attuned to the Element, but for those who are of higher Ranks and creating more powerful enchantments, it is often necessary to use rubies or red Diamonds.