Magma Gold

Geology and occurrence. Petrographically, Magma Gold is a migmatite – a high-grade metamorphic mixed rock that formed through partial anatexis (partial melting) of a pre-existing metamorphic parent rock under extreme pressure and temperature conditions deep in the Earth's crust. In this high-temperature metamorphism the paler mineral portions (quartz, feldspar) melt selectively and concentrate in fluid bands, while the darker mineral portions (biotite, amphibole) remain in the solid state. The characteristic golden-yellow to orange colouring of the “melt bands” arises from incorporated iron oxide and haematite pigments. In the international stone trade the grade is traded as “Brazilian granite” – that is a commercial classification for all hard crystalline, polishable plutonic rocks; petrographically correct is the designation as migmatite. The deposits lie in the Precambrian Brazilian shield; the stone is exported via the ports of Vitória and Salvador.

Appearance. The ground tone is a deep black-anthracite-brown building stone tone with subtle warm brown underlays. Across the surface run characteristic, powerfully flowing vein courses in golden-yellow, ochre-brown, copper-brown and occasionally orange-red tones, which run like molten flows of lava across the dark slab picture. The veining is, as is typical of the material, irregular and flowing, with characteristic swirling movements that give the grade its iconic “Magma” character. Here and there creamy white plagioclase zones or paler quartz lightenings appear. From a medium distance the surface looks dramatic and elemental with a warm effect, like a frozen scene of volcanic eruption; close up one discovers the geological complexity of the vein courses. Every slab is unique – the composition varies strongly between individual slabs.

Technical properties (SC s8856). Bulk density 2,630 – 2,750 kg/m³, compressive strength 170 – 220 MPa, flexural strength 12 – 18 MPa, water absorption 0.15 – 0.30 %, Mohs hardness around 6 – 7. This places the stone technically in the more stable range of the granite and migmatite family and makes it structurally and mechanically suitable for all demanding applications. Resistant to frost and de-icing salt, fully UV-stable and – as a silicate rock – almost completely acid-resistant (quartz, feldspar and mica do not react to acids such as vinegar, wine or lemon). Heat-resistant: hot pots can be set down directly for short periods.

ROSSITTIS range. The surface finishes available from stock are listed in the »Finishes« block further down. From the slabs we produce statement kitchen worktops, islands, bar counters, dining tables, buffet and furniture tops, vanity units, prestige wall claddings with bookmatching, bathroom fit-outs (with proper waterproofing), window sills and special accent elements.

Comparison. Within the family of dramatically veined Brazilian premium migmatites and quartzites, Magma Gold positions itself as the dark, warm “lava look” grade with powerful golden vein courses. Related statement grades are Patagonia (with golden accents on a creamy white ground tone), Verde Eucalyptus (with green bands), Black Forest (with dark bands), Eclipse (the classic black-and-white storm look) and Magma Black (dark and monochrome). Compared with Patagonia, Magma Gold is markedly darker and has more powerful golden veins – a more flaming, “hotter” character. Compared with black granite grades such as Nero Assoluto, the golden veining is absent – Magma Gold lives on its dramatic dynamic of movement. Compared with porcelain marble-look grades such as Optimum Surfaces Zenith Storm, Magma Gold remains authentic natural stone with individual batch variation and a higher standing.

An honest assessment. Magma Gold is the ideal choice for any application in which a dramatic, elemental dark natural stone effect with powerful golden vein courses is wanted. The grade works particularly strongly as a central kitchen island with bookmatching (one of the most iconic application pictures), as a statement wall cladding in prestige residential and hospitality spaces, as a bar counter top and as a bathroom fit-out in luxurious master bath concepts. In neutral rooms, Magma Gold can determine the entire material hierarchy – the grade is dominant in design terms. Anyone looking for a calm, homogeneous natural stone effect should reach for classic hard rocks such as Nero Assoluto Brazil or Bianco Sardo; anyone who wants a controllable look with an identical dramatic character should switch to a porcelain with bookmatching such as Optimum Surfaces Zenith Storm; anyone who prefers the paler natural stone version with golden accents should reach for Patagonia with its warm golden veining.