Here's a fine matrix specimen of ETTRINGITE from the N'Chwanning II Mine, Kalahari, Northern Cape Province, South Africa. The ettringite is bright lemon yellow. I acquired this fabulous specimen from a South African dealer at the Tucson Gem, Rock & Mineral Show. I purchased some specimens from him last year and asked him to bring me some ettringite this year - and this was one of the treasures he brought. Note: this specimen is from the 1980 find, and ettringite is hard to find now.