Diamond shaped object, very low in the sky. Went inside for half an hour, returned it was gone.I was sitting on my porch Tuesday January thirteenth around eight pm, to my right was what I thought was very low star. It was diamond shaped, very bright, just above the hills. I was sitting on my porch Tuesday January thirteenth around eight pm, to my right was what I thought was very low star. It was diamond shaped, very bright, just above the hills.It never moved it just sparkled. I even noticed a passenger plane fly above it.I watched it for about ten minutes or so. I went into the house for no longer than a half an hour when I returned it was gone.I have never seen anything strange, or out of the ordinary in the sky before this.I am a thirty seven year old healthcare worker in the bay area. I would to hear I was not the only one.