I first came across Prestige Cosmetics Shimmering Trio Eyeshadow Dust from their Skin Loving Minerals range when I lived in OZ. I love it so much it has travelled with me all the way from dry Perth to humid Asia to cold UK! :)
I have the Black Diamond, consisting of 3 shimmering colours: black, dark grey, and translucent silver. The sparkling colours give soft metallic effect that's bold but not harsh, and easily buildable. I've played with a combination of these to create many different looks for my eyes.
If you're a mineral eyeshadow virgin, here's how I would normally use it. Firstly, open the triangular cover of the colour I want. Dip dry brush lightly inside the eyeshadow. Brush it off against the triangular cover so the extra powder goes back inside/within the border of the container (the bit that separated all the 3 colours), until I almost can't see the colour. Then I apply it like applying normal eyeshadow. Just use minuscule amount as it really is highly pigmented. If the colour isn't strong enough, pick up some of the dusts around the container border (the leftover of the above), brush it off against the triangular bit, and repeat application. It's actually easier and quicker to do than my instructions. :)
Like other mineral eyeshadows, the dust can be used as it is (dry) or wet to give more definition.
Verdict: if I only have space for one eye product in my luggage, this shimmering beauty is the one I would take.