Create a pyramid - use the squat one. Click on A to bring up the Attributes
dialogue box. Make positive. Check Show Origin Handle. In Rotate X type
180. Exit the Attributes dialoge box.
Select From Front view. Click A and in Rotate Z enter -26.5. Note the
negative sign. This aligns one edge vertically. Exit the Attributes dialogue.
Drag the origin to the bottom corner as shown to the left. Be accurate
here to ensure all the points line up when you Multi-Replicate later.
Select Edit/Multi-Replicate. Enter Quantity=11 and Rotate Y=30. Make sure
all other boxes are set to zero except for the size boxes which should
read 100. Click on the check and the result should be as shown to the
left. Click on the pyramid at the bottom of the screen to select ALL of
the pyramids, (The first one you created will not be selected at this
point). Group them and make the group Positive.
Create a cube. Position and size it so that it looks like the one at the
left. Use the top view to roughly centre it over the pyramid group. Note
that he bottom surface of the cube passes through the lower intersection
of the pyramid surfaces. This is important. Click on A and make negative.
Group it with the pyramid group. Apply the crystal or diamond material
from the glass library and you have your gemstone.