Quartzites are usually very hard and durable metamorphic rocks, which compose mainly of quartz (80% averagely) and were originally sandstones. They have converted into quartzite through heating and pressure. Quartzites have a massive or layered texture, most often in light, gray, yellowish or brownnish tones. Massive quartzites are rarer than layered ones. Quartzites are mechanically so durable, that usually quartzite floors don't even have to be covered during the building. But quartzites can't stand high temperatures. Quartzites are weatherproof rocks, their polish is very durable (thanks to the high quartz content), water absorbency remains between 0.1 to 0.4 mass %, pressure strength is from 120 to 270 N/mm2, bending strength 15 - 25 N/mm2 and the wear-resistance is 3 - 7 cm3 /50cm2.

Mica quartzites form a separate group among quartzites. Mica quartzites were originally sandstones too, but with high clay content. They have converted into mica quartzites through heating and pressure. Big stone blocks are not possible to get from this rock, because they are somewhat similar to slates, because of their layered architecture. Usually these rocks are sold unprocessed with natural surface and as crazy paving tiles. Mica quartzites are generally used in outside conditions. They colour tone is greenish-gray and they have good weather resistance. They are usually installed on thick cement mortar layer. We recommend to use products that improve bonding with mortar. Mica shales are rarely polished, there water absorbency remains between 0.1 to 0.3 mass%, pressure strength is from 150 to 250 N/mm2, bending strength is 25 - 40 N/mm2 and wear-resistance remains in the range 6 to 10 cm3/50cm2.

Mica quartzites:

Massive quartzites: