what is a HILAL (we designed one and got it made)

Hilal (Arabic: ????, hil?l), a crescentthe crescent Moon visible after a new Moon, determining the beginning of a month in the Islamic calendar.

I was trawling through some of our archive material and realised I’d nearly forgotten the  experience we had designing a Hilal to adorn the small Islamic prayer building we worked on a few years ago.  It caps the roof in the manner of a finial adornment.  With some encouragement from our client we worked out this crescent moon shape as a geometry  generated from intersecting spheres.  It was produced by a local maker who adopted modern  machining principles to create from solid aluminium.