Remember good ol' Master of Orion? And do you remember the alien race known as the Silicoids? For that matter, remember Starcontrol and the Chenjesu? They were crystalline organisms based on silicon.
Right, so... what's the deal here, how do they work? I believe there is fluff about the Chenjesu needing an energy rich environment in order to thrive - perhaps that means an irradiated planet, or one with a particular active electromagnetic field, or something... They orbit Procyon which is a binary system, the primary being an F-class (brighter than our sun) and the secondary being an A-class (ie white and hot)
What is their motive power? Do they crawl, walk, slide or something? What do they use to manipulate their environment: tentacles? Fingers?