Shape shouldn't define textures, or rather we should be able to break the mould (lol) that ties any shape to a material.
They don't define textures, but pieces have more than "textures do this" and "shapes do this." It all has to come together to fulfill a specific purpose, and the shape is what's fighting this piece the whole way. It's not uncommon for humans to relate shapes to specific purposes.
However if you have to maintain a grave shape then good luck to you. Is it impossible? Probably not, but you're definitely going to have to fight hard against the predisposition.
Aside from that I think the most glaring problem is that your textures are coming off as noisy, or "dithery" even though there isn't any immediate dithering patterns. For example, the line going up the interior of the right side does it. This fights what our minds have come to expect of gelatin because it's such a smooth texture, and dithering causes the opposite effect. Also, something important you need here is some high contrast highlights. Think of a glassy, or wet surface. That's how gelatin reacts to light, so it won't hurt to have some more dramatic highlighting. I can't say I know what's going on with the patterns going on inside(or on the front) of the gelatin. Is it needed? Because it doesn't seem to add much to what you're hoping to accomplish and in my opinion only complicates matters further.