Striking monochrome; Agate dressed in deepest black Veins whisper lace white

I can be plowed or explored, harvested or and area of study.

In one moment I’m a dragon, a castle, a ship, a giant that shifts with the breeze’s soft slip. You lie on the grass and name what you see, but none of those shapes are truly me.

What do you call a snail working on a ship?

A shield of fabric in your hand, When skies weep, I take my stand. Above your head, I spread wide, To keep you dry from teardrop tide.