"EXTRA BLUEUKRAINE" L 10 - the registered trademark of the labradorite extracted on the field Dobrynskom-1
Uniqueness of labradorite, as well as each decorative stone depends also on the field. In Ukraine about six operating pits on extraction of labradorite which are mainly in the Zhytomyr region. The drawing, physicomechanical properties and a chemical composition has each appearance of labradorite.
In the international qualifier of the Gemological center of Ukraine this look is registered under the EXTRABLUEUKRAINE L trademark 10, and possesses the following physicomechanical properties:
· True density (g/cm ³) - 2,76-2,95;
· Average density (kg/m ³) - 2708-2941;
· The general porosity () - 1, 01-1,72;
· Water absorption (%) - 0, 14-0, 27;
· Firmness on compression (kgf/cm ²):
vB a dry state - 1548-2037;
vpri saturation by water - 1314-1664;
vposle of 50 cycles of freezing - 1250-1394;
· Coefficient of decrease in durability at saturation by water - 0,7;
· Frost resistance brand - F-50;
· Deleting indicators - 0,69-0,8.
Labradorite of the field meets for physicomechanical properties and TU the requirements of DSTU BV. 2.7-59-97 "Blocks from a natural stone for production of facing products". By a radiation and hygienic assessment labradorite answers Ι to a class (23,0±21,6% of Bq/kg) and his use is unlimited, and processing will not lead to increase of a radiation background that is confirmed by the relevant documents (the certificate and the radioactive passport).
Thanks to the fact that in the labradorite extracted in the field Dobrynskom-1, in difference from other fields there are practically no iron impurity the possibility of formation of oxidation (rust) and so-called "potek" is excluded.