11. The apse is heptagonal and has in its lower half seven pointed arches filled with opus sectile . 12. For example, gold is sectile but pyrite ( " fool's gold " ) is not. 13. As such, these eleven mosaics cover virtually the whole period of opus sectile work by Powell's. 14. Similarly, for works that use larger pieces of stone ( or tile ), opus sectile may be used. 15. From 1937 until 1947, O'Brien worked on 22 opus sectile panels for the Protestant Church in Ennis. 16. sectile and has a shining streak; hardness 2.5, specific gravity is 7.2 7.4.17. "' Pharmacosiderite "'is a hydrated vitreous and resinous, and it has conchoidal, brittle and sectile fracture. 18. There is a decorated floor mosaic laid in the technique of " opus sectile " within the basilica and several rooms have been unearthed. 19. "On the morning of Monday 9th March 2009, there will be a formal unveiling of the restored opus sectile in Long Tower. 20. The central part of the mosaic is composed of geometric alternating square panels with each side measuring and realized in the opus sectile technique.
