Pink Faceted Ruby Gemstones, Cut Pulled Rubies Stone:Bubbly Diamond Cushion, 11.6x9.2mm, 3.72ct Note that the smaller squares

Note that the smaller squares can sometimes be a bit more trapezoidal

it is challenging to grow these crystals in very large sizes

where it is used in some particular high-end laser systems

Titanium sapphire is a very unusual variety of sapphire

and is very difficult to cut

Pink Faceted Ruby Gemstones, Cut Pulled Rubies Stone:Bubbly Diamond Cushion, 11.6x9.2mm, 3.72ct Note that the smaller squaresThese are faceted pink rubies, grown using the Czochralski pulling methods. Like all rubies they have a high hardness of 9, great brilliance and glow red under UV. These might have been intended for lasers, or perhaps luxury watches. Some pieces have bubbles. The most classic gem produced by science is laser ruby. While material of this color would be called 'pink sapphire' in a gemological context, in laser science all corundum doped with chromium is