Quartzite

Listed in our range under Granite.

Tropical Storm

Tropical Storm is an expressive Angolan hard stone with a dramatically deep black groundmass and spectacular white, golden and bronze vein bands that run through the slab surface in flowing, storm-like movement patterns. Classified in the trade as quartzite/granite (a trade convention for African hard stones with a dramatic look). Also carried internationally as Tropical Night Granite and Tropical Storm Black Granite; used for statement wall cladding, bar counters, designer kitchen worktops, bookmatch settings, fireplace surrounds and prestige internal surfaces with a dramatic, storm-like material effect.

Tropical Storm wird in verschiedenen internationalen Quellen unterschiedlich klassifiziert — als Quarzit, Granit oder Gabbro/Anorthosit, je nach petrographischer Bewertung. Die hohe Rohdichte (2.690–2.750 kg/m³) deutet auf eine basisch-metamorphe Hybrid-Mineralogie hin. Bei ROSSITTIS klassifizieren wir Tropical Storm handelsüblich in der Granit-Familie gemäß weit verbreiteter Trade-Konvention für afrikanische Hartsteine mit dramatischer Optik. Wichtig: Es gibt einen unverwandten brasilianischen Quarzit mit ähnlichem Trade-Namen 'Tropic Storm' — bei Bestellung die angolanische Herkunft spezifizieren.

Quartzite Angola 2.720 kg/m³

Available as: Slabs

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About Tropical Storm

Tropical Storm shows an exceptionally dramatic slab character with one of the most spectacular storm looks in the worldwide natural stone range. The groundmass is deep black with anthracite zones, shot through with characteristic white, golden and bronze vein bands that run in dynamic, storm-like movement patterns — like frozen cyclones, cloud formations or cosmic currents. The flowing lines alternate between fine white-silver bands, stronger golden currents and subtle bronze accents that lend the slab surface an exceptional optical depth. Here and there, pale cream mineral clusters set additional light accents in the dark storm zones. The designation 'Tropical Storm' describes the characteristic material effect aptly — a tropical storm front set in stone, with dramatic vortices and currents. On a polished surface the stone develops an exceptional dramatic depth — the black zones intensify, the golden vein bands glow warmly and the whole stone reads like a living geological weather event.

Geologically, Tropical Storm is carried in international trade as an Angolan hard stone — the petrographic classification varies between quartzite, granite and gabbro/anorthosite, depending on the source. The database classification as quartzite (with metamorphic foliation) fits the visual migmatitic, flowing band appearance; some international sources classify the material as gabbro/anorthosite (a basaltic plutonic rock) — this fits the high bulk density (2,690–2,750 kg/m³). At ROSSITTIS we classify Tropical Storm in the customary trade manner in the granite family, in line with the widespread trade convention for African hard stones with a dramatic migmatitic, storm-like look. Several synonyms circulate in international trade: Tropical Night Granite, Tropical Storm Black Granite and Angolan Storm.

Technically, Tropical Storm shows exceptionally strong values: bulk density 2,690–2,750 kg/m³ (very high — comparable with high-density gabbro/anorthosite selections), compressive strength 200–230 MPa (very high), flexural strength 12–13 MPa, water absorption 0.25–0.34 % (low), Mohs hardness 6–7. Full acid resistance confirmed as a silicate rock — wine, lemon juice, vinegar or sanitary cleaners leave no etch marks as they would on marble or limestone. Tropical Storm is therefore fully practical for the most demanding internal and external applications.

At ROSSITTIS we carry Tropical Storm as a raw slab in 15, 16, 17, 20 and 30 mm thickness (standard thicknesses plus finer wall tile thicknesses) and for project-specific cutting to size. The finishes available from stock are listed in the »Finishes« block further down.

Compared with other black-and-gold statement hard stones, Tropical Storm is an exceptional choice with its specific tropical storm look: Black Cosmic (a Brazilian quartzite with a similar storm look) is related in character; Mascarello (Brazil, with brown-burgundy tones) is warmer; Black & Gold (an Italian marble with golden vein traces) is more acid-sensitive; Tempest Black (a Brazilian migmatite) has a similarly dramatic look but with red almandine garnets instead of golden vein bands. Within the black-and-gold statement hard stones, Tropical Storm is among the most expressive choices, with a dramatic flowing movement structure. For architectural projects with the highest staging ambitions — designer bar counters in premium restaurants and bars, statement kitchen islands with bookmatch installation, prestige wall cladding in high-end hotels and spas, exclusive fireplace surrounds, designer settings with a dramatic, warm statement character — Tropical Storm is an exceptional and unmistakable choice.

Technical data

Guide values for the stone type, taken from manufacturer and test reports. Natural stone is a natural product — individual batches and slabs can differ. For critical applications, request slab-specific test data.

Rohdichte 2.720 kg/m³

Druckfestigkeit 215,0 MPa

Biegezugfestigkeit 12,5 MPa

Wasseraufnahme 0,30 %

Finishes

Tropical Storm is available in a range of finishes. The finish affects appearance, feel and the care it needs.

Poliert

Politur ist die klassischste Veredelung für Quarzit — eine glänzende Oberfläche mit höchstmöglicher Farbintensität und ausgeprägter Tiefenwirkung. Je nach mineralischer Zusammensetzung kann die Wirkung stellenweise mattglänzend sein. Als Silikatgestein vollständig säurebeständig und kratzhart — ideal für Küchenarbeitsplatten und Sichtflächen.

Satiniert

Die Oberfläche wird gebürstet — weichere Minerale werden gezielt entfernt, es entsteht eine leichte Tiefe und mattes Erscheinungsbild. Geaderte Quarzite erhalten so eine besondere Charakteristik. Säurebeständig und kratzfest, pflegeleicht im Alltag — beliebte Alternative zur Politur in modernen Küchen und Wohnräumen.

Care & fabrication

As an Angolan hard stone, Tropical Storm is a robust stone with low water absorption (0.25–0.34 %), full acid resistance and very high compressive strength. Wine, lemon juice, vinegar, cola, sanitary cleaners or descalers leave no etch marks as they would on marble or limestone — the stone is considerably easier to maintain and is ideally suited to intensive everyday use.

For internal applications we recommend a silane- or polysiloxane-based sealer at first installation. On polished surfaces, renewal every 5–8 years is sufficient; on heavily used kitchen worktops or bar counters, check every 2–3 years.

Daily care is carried out with a pH-neutral natural stone cleaner and a soft cloth or microfibre mop. Clear warm water is usually sufficient. Acidic cleaners are unproblematic in principle, but should nonetheless not be used, because they can attack the sealer. The finishes available from stock are listed in the »Finishes« block further down.

For kitchen worktops, Tropical Storm is outstandingly suitable: cut- and scratch-resistant (Mohs hardness 6–7), insensitive to heat (hot pots and pans can be set down directly for short periods, but prolonged heat exposure above 200 °C should still be avoided), acid-resistant and with excellent stain repellency. The expressive storm-like movement structure conceals small signs of use remarkably well.

For external applications we recommend a project-specific check of the frost resistance data sheet before ordering. If released for external use, a satin-honed or textured surface makes sense for slip resistance. Polished external surfaces can show minimal loss of gloss after years in positions with heavy UV loading.

Frequently asked questions

What is Tropical Storm geologically?

Tropical Storm is carried in international trade as an Angolan hard stone — the petrographic classification varies between quartzite, granite and gabbro/anorthosite, depending on the source. The high bulk density (2,690–2,750 kg/m³) points to a basic metamorphic hybrid mineralogy. The Angolan origin is consistently documented in the international market. At ROSSITTIS we classify Tropical Storm in the customary trade manner in the granite family, in line with the widespread trade convention for African hard stones.

What synonyms are there?

In international trade, Tropical Storm also runs under the designations Tropical Night Granite, Tropical Storm Black Granite and Angolan Storm. IMPORTANT: there is an unrelated Brazilian quartzite with the similar trade name 'Tropic Storm' — that is a different material. When ordering we recommend specifying the origin (Angola) to avoid confusion.

Which technical values does Tropical Storm have?

Exceptionally strong values: bulk density 2,690–2,750 kg/m³ (very high), compressive strength 200–230 MPa (very high), flexural strength 12–13 MPa, water absorption 0.25–0.34 % (low), Mohs hardness 6–7. Full acid resistance confirmed as a silicate rock. These values qualify the stone fully for demanding internal and external applications.

What does the storm look mean?

The characteristic 'storm' look in Tropical Storm arises from flowing, winding white, golden and bronze vein bands that run through the black groundmass in dynamic, vortex-like patterns. The movement structure recalls frozen cyclones, cloud formations or cosmic currents — hence the trade name 'Tropical Storm'. This spectacular slab appearance makes the material one of the most expressive statement choices worldwide.

Is Tropical Storm suitable for bookmatch installation?

Outstandingly suitable — bookmatching is in fact the typical way of staging this material. In bookmatch installation (two slabs laid as mirror images), the flowing, vortex-like storm bands produce symmetrical, almost surreal large-scale motifs that read like mirrored weather events. A very fitting setting for prestige wall cladding, bar counters or designer statement surfaces in hotel lobbies, high-end restaurants and spas.

Is Tropical Storm suitable for a kitchen worktop?

Outstandingly suitable. With Mohs hardness 6–7, low water absorption (0.25–0.34 %), very high compressive strength (200–230 MPa) and full acid resistance, the stone is cut-, scratch- and heat-resistant and does not absorb the acids in wine, lemon or vinegar. The expressive storm-like movement structure conceals small signs of use remarkably well and suits designer kitchens with a dramatic material staging.

Which finishes are available for Tropical Storm?

The finishes available from stock are listed in the »Finishes« block on this page.

Where does Tropical Storm come from?

Tropical Storm comes from Angola — the precise quarry identification is to be confirmed with the importer on a project basis, because no direct standards documentation is available for this specific selection. The mineralogy and appearance point to an African hard stone complex, possibly related to the Angolan anorthosite selections such as Angola Moon Luanda.