This is druzy quartz (druzy meaning lots of tiny, sparkly crystals covering the whole of the piece) with growths of sphalerite and galena. Sphalerite is usually a pretty red or orange color, and galena looks a lot like graphite. Below is another example, with nice, big chunks of sphalerite.
Here, on the left, is a rock formed from the minerals surrounding a white smoke hydrothermal vent. You can't really tell here, but it's pink, smooth and translucent. On the right is a calcite stalactite.
On the left, this is a specimen of nepheline. You can't really tell by this picture, but each of these crystals is a hexagon, into which you can see. It's really nifty. On the right is vanadinite. It is sooo sparkly.
Below on the right is another example of vanadinite, and is some of the largest vanadinite crystals I've ever seen. On the left is what's called a phantom quartz, because it's clear, and inside it you can see other "ghost" stones.
This is my favorite piece. It's a fluorite stalactite. I love stalactites. I love that they take so long to form, and I love the smooth, waxy feel of them. This one in particular, when wet, has phantoms all along each protrusion.
Below are two more examples of fluorite. The one on the left is in a white chalcedony matrix, and the one on the right is purple fluorite on a quartz matrix.
Below, on te left is a piece of hemimorphite, which is really vibrant, and on the right is cinnabar growing on dolomite. I've been looking for a decent specimen of cinnabar for a long time, because it reminds me of strawberries and cream, and I found this one. You can't really tell by the picture, but it looks yummy. Too bad that the main component of cinnabar is mercury.
So, there you have it. I have more at home, which I've blogged about previously. I love my rocks. I started collecting them when I was a young child, when I started attending a new day care (nursery school? I can't remember). I remember how it started, though. I was really shy, and didn't socialize with all the other kids, so during recess, the teacher gave me a little tupperware container, took me to the playground, the base of which was smooth pebbles, and taught me how to find pretty rocks. I've been collecting them ever since.