Recently, I needed to create a vector graphic rhinestone for a client project I was working on, so I googled "vector diamond tutorials" and then "vector rhinestone tutorials" and really had a hard time finding anything useful. So, left to my own devises, I came up with what I think is a pretty good-looking diamond, and I thought I'd share how I did it. This tutorial will show you step-by-step how to create the diamond below in Illustrator CS4.
Part 1: Creating the Basic Shape
1. I looked at lots of images of solitaire diamonds so I could get an idea of the geometric pattern of a diamond's facets. To create my vector diamond I started out by creating a square using Illustrator's rectangle tool (use the shift key while drawing the rectangle to keep the proportions even for a square). Then I duplicated my square by dragging the square's layer in the layer palette into the new layer icon, which creates an identical layer directly above the original layer. Rotate the second square 45 degrees so the two overlaid squares make the shape below. Note: To make the different layers easy to identify, I made each a different shade of gray.
2. From these two squares we want to make three different sets of shapes: one octagon in the center (where the two squares overlap), and two sets of triangles (where each square overlaps the other). To do this we'll need the pathfinder palette and three sets of our squares. Select both squares in the layers palette and drag them into new layer icon to create duplicates directly above the originals. With the top set of squares active, click the intersect button in the pathfinder palette. This will create the center octagon. Duplicate the squares again, and this time click the Minus Front button in the pathfinder palette. This creates one set of four triangles. Now reverse the layer order of the original squares, and with both layers active, click the Minus Front button again to create the second set of four triangles. You should now have three layers: the octagon layer, and two grouped layers of triangles, as in the figure below.
3. Next use the circle tool to create a circle a little larger than our existing collection of shapes, and send it to the back (ctrl/cmmd + shift + [ ).
4. The next sets of facets will need to be drawn with the pen tool, so we'll need to create a guide to help us out. Using the line tool, create a line that passes through the circle and lines up at the corner where two of the outer triangles meet, as shown below.
5. Now we're going to use the pen tool to create an irregular diamond shape that follows the straight edges of the two adjacent triangles, with an outer point that touches the edge of the circle where our guide line hits, as shown below (I outlined the shape in red for demonstration purposes only). Once you have this shape, you can delete the guide line layer.
6. We need a total of eight of this facet shape, so we're going to duplicate the layer and then rotate it 45 degrees (right click on it, and choose Transform > Rotate from the right click menu). Place the new facet at the corresponding juncture between two triangles, and repeat this step six more times. When you're done it should look like the figure below.
7. We're almost done creating the facets--just one set left! The outside-most facets are not their own shape, but simply what's left of the circle showing behind the rest of the facet layers. We need to create facet shapes over top of that circle, and each of the outside-most facets needs to be two facets and not just one. Using the pen tool, trace just half of an outside facet shape as shown below. Duplicate that facet and reflect it horizontally. Line it up with the original facet shape so that the two flat edges meet and their rounded edges continue the shape of the circle. Now duplicate this facet set, rotate it 45 degrees, and line it up at the next interval. Repeat this step six more times, until your diamond looks like the figure below. Now we have all the facet shapes we need for our diamond.
Part 2: Adding Color
8. Now we're ready to color our diamond. Selecting all our facet layers, we're going to add a custom gradient. I started with the white to black gradient available in the default colors palette and changed the white to a very pale gray, and then added a dark blue between the pale gray and the black, moving the blue closer to the black end of the spectrum. When you add the gradient to all your facets at once, it will look like the figure below.
9. At this point, it doesn't look very realistic with all the gradients lined up in the same direction, so next we'll want to use the gradient tool to align each facet's gradient individually. This is easiest to do if all layers are ungrouped. Just adjust each facet's gradient until you're happy with how it looks. If it still looks rough and unfinished to you, don't worry; the next step will help polish things up nicely!
10. You should still have a circle layer at the very bottom of your layer stack. Duplicate it by dragging and dropping the circle layer in the layer palette into the new layer icon, and bring the duplicate all the way to the front. Then you're going to create a new custom gradient with white at either end, and a closely-packed rainbow spectrum in between (and off center a bit). If you are working in Illustrator CS4, change the opacity of the two end points to 0%. Fill the new circle with your custom gradient, and rotate the angle of the gradient about 45 degrees.
11. Next change the transparency settings of the rainbow circle so that the blend mode is set to color burn, and adjust the opacity as you see fit. The rainbow layer mixes with the gradient facets to create the look of refracted light. I ended up moving the rainbow gradient within the circle so that it ran across the top of my diamond instead of the bottom.
12. Last, we add a few details to suggest the diamond's luminosity. I created some sparkles with the pen tool, and added a little glow behind them by drawing a white circle with the elliptical tool and running a Gaussian blur filter over it. Then I set my diamond over a rich, blue gradient background. To create the look of light reflecting through my diamond onto the background, I duplicated the diamond's circle layer two more times and offset one circle to the top left of the diamond, and the other to the bottom right. I filled the bottom right circle with a custom gradient that had a deep black-blue on one end and a sky-blue on the other, and set it to radial (making sure the lighter blue was on the inside). I then ran a Gaussian blur filter over the circle, and set the blend mode to overlay. I used the same radial gradient on the upper left circle, only I reversed the colors so the dark blue was in the center and the light blue on the outside. I ran the same Gaussian blur filter on this circle, and set its blend mode to screen.
And there you have a beautiful, luminous vector diamond illustration. I'm sure other precious stones could be created from this tutorial with the use of different colored gradients. If you find this tutorial useful, or create your own art with it, I'd love it if you left me a comment or a link to your creation! Happy creating!