- Well, it feels kind of oily. Seems heavier than ordinary water.
- It probably has an entirely different mineral content.

11 seconds sound clip from the The Angry Red Planet movie soundboard.

You can hear this line at 00:54:18 in the Blu-ray version of the movie.

Quote context

[...]

- I've been curious as to what's on the other side of that ridge. Let's go.

- Now there it is, a Martian lake.

- It has that same feeling of deadness.

- No, wait a minute, Iris.

- It's all right. No abnormal radiation.

- So there's water on Mars after all. Besides the polar icecaps, I mean.

- If it is water.

- Well, it feels kind of oily. Seems heavier than ordinary water.

- It probably has an entirely different mineral content.

- I'm sure it couldn't sustain life, at least not life as we know it.

- I wonder what's on the other side?

- Well, tomorrow we'll bring the boat. The lake isn't so wide. We'll have a look.

- It's getting late. We meet any more creatures like that last one, I'd hate to have to fight 'em in the dark. Come on.

[...]