Lattice Quartz with Foitite Cluster, Erongo Mountains Namibia

This Lattice Quartz with Foitite Cluster is a distinctive specimen from the Erongo Mountains of Namibia, centred around a dramatic group of broad, milky-white quartz crystals. The crystals form an intricate interlocking arrangement, with darker Foitite-rich mineralisation concentrated between and beneath the quartz. Several sharply defined smaller quartz crystals add clarity and detail around the darker mineral-rich areas, creating an appealing contrast within the predominantly pale specimen.

Specimen Details

• Mineral: Lattice Quartz with Foitite
• Quartz Chemical Formula: SiO₂
• Foitite: Tourmaline-group mineral
• Locality: Erongo Mountains, Erongo Region, Namibia
• Geological Setting: Erongo granite and associated pegmatitic environment
• Geological Age: Cretaceous
• Quartz Colour: White to milky and translucent
• Foitite Colour: Dark grey to black and brown
• Transparency: Translucent to locally transparent
• Crystal Habit: Interlocking lattice-like quartz crystals with smaller associated crystals
• Associated Minerals: Foitite and feldspar
• Weight: 228 g
• Size: 79 × 60 × 60 mm
• Preparation: Professionally cleaned
• Base: Trimmed flat base
• Display: Ready for display

The Erongo Mountains are one of Namibia's renowned mineral-producing regions, particularly known for unusual quartz formations and complex mineral associations. Among the area's most distinctive collector specimens is Lattice Quartz, also known as Gitter Quartz, named for the remarkable lattice-like arrangement created by its intergrown crystals.

The unusual structure of Erongo Lattice Quartz results from the way quartz develops in association with feldspar. Quartz crystals can grow epitactically upon the surfaces and edges of earlier feldspar crystals, producing unusual intersecting arrangements. As the feldspar is later altered or dissolved, the remaining quartz can retain an open, three-dimensional framework that gives Gitter Quartz its characteristic appearance.

This specimen offers a particularly interesting variation on that theme. The main body is dominated by several large, broad quartz crystals, giving the piece a substantial and almost architectural appearance. Their softly milky surfaces contrast with smaller, clearer quartz crystals that emerge from the spaces between the larger forms.

The darker mineralisation is especially noticeable around the central and lower portions of the specimen. Foitite, a member of the tourmaline group, occurs in dark clusters and coatings associated with the quartz. These darker areas create natural pockets of contrast, drawing attention to the intricate relationships between the different generations of crystals.

Several viewpoints reveal different aspects of the specimen. From the principal display angle, the large quartz formation dominates the piece, while the side and rear views reveal additional interlocking crystals and darker mineral-rich areas. This gives the specimen a pleasing three-dimensional character, rather than presenting as a simple flat cluster.

The central quartz formation also shows interesting natural surface textures and internal variations in translucency. Some crystals are softly frosted and milky, while smaller crystals around the darker mineralisation are noticeably clearer, allowing the viewer to explore the specimen's detailed mineral growth at close range.

At 228 grams and measuring 79 × 60 × 60 mm, this is a substantial cabinet specimen with a strong display presence. It has been professionally cleaned and fitted with a trimmed flat base, allowing it to stand securely and making it easy to incorporate into a mineral cabinet or collection display.

Quartz has a Mohs hardness of approximately 7, although the projecting crystals and intricate intergrowths can be more vulnerable to impact than the hardness of the mineral itself suggests. Handle carefully and avoid knocks, drops and abrasive cleaning.

With its bold central quartz formation, intricate lattice growth and contrasting Foitite mineralisation, this Erongo specimen captures the unusual character that makes Namibian Lattice Quartz so sought after by collectors. A fascinating piece to examine from every angle and a striking addition to a quartz collection.