UNGO NAVA S.A. enterprise owns a concession to explode an ornamental limestone flag that includes five miner demarcations, called UNGO NAVA VIVANCO no. 4.147.

This ornamental stone or flag is exploded in a quarry close to Vivanco de Mena (Burgos) with many areas of extractions. Here, large size stones are obtained, stones from 3 to 10 cms thick and compact packs up to 40 cms, which are sold with irregular shape or cut in factory. Paving stones and other square or rectangular pieces used for paving masonry, plinths, walls and façades are manufactured for either chalets or cottages. This gives the building a rustic look.

The massive sedimentation that gave as result this rock, came to happen during the low Turonens in the central side of the bowl tha was pretty deep and where the energy index was low.

The obtained rock is a packstone limestone (biochrimite), very homogeneous, with a very fine grain size, medium gray colour, compact and slabed. It contains a percentage of quartz in very fine grain between 8 and 14%, a little amount of iron and magnesium minerals and many types of fossils ("calcisferas, globigerinidos, espiculas de esponjas, bivalvos, equinidos").

Attempting to its physical characteristics, behaviour on its application and resistance to the weather conditions, just say that it has a very low water absorption index, high resistance against frosts and a splendid behaviour to bend and compression strength. Its specific average weight is 2.648 Kg/m³.

TEST RESULTS & COMMENTS
(Data:CTM Centro Tecnológico del Mármol)

This is a low-absorption (0.5%), low-porosity (0.5%) stone, which makes it suitable for indoor flooring. Its density (2670 kg/m3) is similar to that of most marbles & compact limestones.

Its abrasion resistance (21.0 mm) is typical of marmoreal limestone, indicating good durability of surface finish under heavy pedestrian use.

Its bending strength (27.1 MPa) is very high for a limestone, and is higher than almost all known marbles, limestones and granites except some slates. This means that it can be used at very low thicknesses in general for flooring and cladding.

Tests for resistance to freezing show no significant changes in bending strength and tests for resistance to ageing via heat shock show no changes in mass or modulus of elasticity. The material is therefore practically unchangeable in exposure to freezing and heat shock.

Wet skid resistance on sawn surfaces (USRV = 70) exceeds the toughest requirements (Class 3 > 45) in the Technical Building Code.