Photoshop : Gem Logo Icon

1. New Document/Canvas
Start by making a new document in Photoshop. I used a small size of 300 x 300 pixels with default Resolution (72).
You might want to add in a background such as a light-grey gradient now.

2. Enable Grids/Create Shape

Now let’s start the gem’s shape. Firstly you’ll need to enable grids (View > Show > Grid in the Photoshop menus), then go to Edit > Preferences > Guides, Grids & Slices and change the grid size to 10 pixels.

After enabling the grid, find and get out the Polygonal Lasso Tool then use it to make the following shape:

Make a new layer and fill your gem-shape selection with a color.

Note that the color doesn’t matter at this time.

3. Metal Effects (Gradients)

Now you’ll need to divide your gem shape up into a few different sections. You can do this by following these few simple steps:
Make a selection using the Rectangular Marquee Tool.
Right-click the selection (with your selection tool still active) then go to Layer via Cut)
Repeat this until you have an image like mine below.

So, if all your different sections are on separate layers, you’ve done everything right. Right-click the first layer of these and go into the Blending Options. After doing so, apply this Gradient Overlay. Repeat this for every layer, except you will need to change the angle of the gradient for each one.

In the below image I’ve written down what angle each of the gradients used were.

Now it’s time to move your layers back together and merge them (CTRL+E)

To finish this step off I applied this Drop Shadow to my leftover layer

4. Adding the Inner Part
Create a new layer. Now select your previous layer that you merged together (Hold CTRL and Click the layer thumbnail) then lastly contract the selection by 3-4 pixels (Select > Modify > Contract.

After making this selection you can fill it with a gradient (preferably red) I used a gradient of #f80000 and #940404.
I made my Radial gradient from the bottom corner to the top middle area

After doing all this you can add this Inner Shadow as an optional touch.

5. Adding Optional Touches
Using the Gradient Tool make a #f80000 to transparent gradient inside of the gem at the top right.

Again select your main gem layer then contract the selection by about 2 pixels. Create a new layer then make a white to transparent gradient from the top left to the middle area of your selection.

Lower the opacity for this layer to about 15-30%.

6. Finished

I finished this off by adding in a symbol from the custom shapes that come with Photoshop, and also making a few smaller versions.
You can make some smaller versions by merging all of the layers together then resizing them (CTRL+T)