Fellow, Gem-A(GtBr) / Graduate gemologist GIA (USA) / Certified Evaluator (SA)
Email: firstname.lastname@example.org / Tel: (011) 784 0172 / Cell: (082) 469-6024
From left to right: Morion gwindle (fig 1), A cluster of elongated quartz crystals (fig 2), Cactus amethyst (fig 3), Amethyst Geode (fig 4)
In Europe mineralogists and gemmologists recognise seven crystal systems. However in America they have reduced this to six by combining trigonal minerals with those that conform to the hexagonal system.
Therefore such commonly encountered trigonal quartz gems as amethyst, citrine, rock-crystal, etc are classed as being hexagonal in the USA.
In addition to a virtually endless range of hues, quartz crystals occur in a wide variety of habits that range from simple single crystals to the tight horizontally stacked form known as a gwindle.
Amethyst sceptre (fig 5), Japanese twin (fig 6), Rock crystal (fig 7), Rose Quartz xls rare (fig 8)
Fig 2 illustrates a cluster of elongated quartz crystals from D.R. Congo. The sceptre form crystal, fig 3 exhibits a fascinating range of hematite, goethite, ilmenite, pyrite etc as mineral inclusions.
When two quartz crystals butt onto one another at right angles they form what is known as a Japanese twin. Twin crystals of this type are very rare and desirable collectors’ items (fig 6).
Typically the parent crystal in this specimen is almost completely enclosed by the numerous daughter crystals (fig 3).
Rose quartz (fig 8) is a common mineral in its massive form. However crystals of rose quartz are very rare. The limited number of specimens that come on the market generally originate from one two mines in Minas Gerais, Brazil.
The amethyst geode specimen (fig 4) originated from the bed of the Gwaai River near Tjolotjo, Zimbabwe.