Glass Orb

First open up a new document with a transparent background

I used 300x300. Create a new layer and call it "Orb Base"

Then select the circle marquee tool and draw a circle on the canvas (use shift to make it a perfect circle)

Fill the selection in black

then go to layer styles and apply these settings.

After you have done this, you should have some thing like below

The next thing to do is add the high light

create a new layer called "highlight" and draw another circle selection, like in the picture below.

Now we need to add a gradient.

we use the gradient which goes transparent at the end, and we have it stating white. (as in the picture)

Click to enlarge

then draw on your gradient, from top to bottom, like in the picture below

And you should now have something that looks like this

Deselect the shape (control+d)

The highlight stands out to much so we need to blur it, we use a Gaussian blur.

Depending on the size of the orb you may need a higher setting, but for this size a setting of about 3 should be fine

After applying the blur you should have something that looks like this

If you want to add a logo to the orb then place it below the highlight layer.

and you should have an nice effect like the one below

nice effect always make the orb bigger than required, as when you make it smaller it will stay good quality.

You can change the colour of your orb by adjusting the settings of the gradient over lay. (i have shurnk my orb and change the background colour and added a reflection)