Glass
Glass is one of those peculiar words that at first glance appears correct, succinct, perfect. But take a moment to inspect it more closely, wait a while and let your eyes pore over it, you will find that after a few moments it appears odd, somehow misspelt.
Glass is also a peculiar form of matter formed originally from sand, yes that's right, as odd as it seems that is where the origins of glass are found.
Glass by its very nature is a very useful material being able to both deflect and refract light, in much the same way as water. It's many uses have been boon to everyone with defective vision (such as myself).
Polished glass is perfectly opaque as anyone who has walked into a glass door will attest, but it also has fragile characteristics in unreinforced form, it is fragile in the extreme and once shattered it can splinter into shards so sharp at the edge, the slightest touch will cut through flesh instantly.
Because of its fragility, it is said that people who are easily hurt emotionally have a heart of glass.
However, the object of this challenge is not to describe glass, but to describe the word, and as I have already done that, my challenge is complete.