Sunbright
Granite
Structure: SUNBRIGHT is a beige coloured gneiss (old Saxonian miner designation) with brownish volumes. It has a light structure from palely beige feldspar and highly transparent quartz. It's clearly direction-oriented, with only a few and very small black sheds of in-regular biotite (dark mica). SUNBRIGHT's strongly changing texture makes sampling more difficult. In order to obtain a general impression of the rock, prototype sample are not sufficient usually. To get the general impression and the effect of the rock a large-scale sampling is recommended.
Characteristics: After the MOHS´ hardness scale (1 = chalk, 10 = diamond) possesses SUNBRIGHT a degree of hardness from 6 to 7 and ranks thus among the hard rocks. It is to a large extent frost and polish-steadily.
Emergence: SUNBRIGHT developed as transformation rock (metamorphic rock) due to rise in temperature, increase in pressure and/or fluid supply (e.g. H2O, CO2) within the earth's crust. Temperatures prevailed over approx. 600°C and pressures below 1,4 GPa. This corresponds to earth's crust depths from approx. 45 to 50 km depth. The structure is medium to coarse-grained. The regulation of the crystals is well visible. The rock is lagig stringily to goarsely schistose and often visibly ribboned.
Age: approx. 600 millions years (Precambrian).
Use: Interior and external architecture; Floor mats, stairway steps, kitchen sill plates.