Starburst quartz
The inclusions of grey metallic haematite (an iron oxide, see http://tinyurl.com/nngtpnh) are overgrown with needles of rutile (a titanium oxide) in a gemmy quartz. The planes of rutile needles are oriented with the crystallographic growth of the quartz to produce a hexagonal pattern, revealed to great advantage in this freeform carved gem.
Loz
Image credit: Lawrence Stoller
Starburst quartz
The inclusions of grey metallic haematite (an iron oxide, see http://tinyurl.com/nngtpnh) are overgrown with needles of rutile (a titanium oxide) in a gemmy quartz. The planes of rutile needles are oriented with the crystallographic growth of the quartz to produce a hexagonal pattern, revealed to great advantage in this freeform carved gem.
Loz
Image credit: Lawrence Stoller