Containing magnesite, magnesia in the form of

68.15 Articles of stone or of other mineral substances (including carbon fibres, articles of carbon fibres and articles of peat), not elsewhere specified or included. 68 15.10 - Non-electrical articles of graphite or other carbon 68 15.20 - Articles of peat - Other articles : - - Containing rnagnesite, doIomite or chrornite 6815.99 - - Other 68 15.91 This headin covers articles of stone or of other mineral substances, not covered by the earlier headings o this Chapter and not included elsewhere in the Nomenclature; it therefore excludes, for example, ceramic products of Chapter 69. f The heading covers, inter alia : (1) Non-electrical articles of natural or artificial graphite including nuclear carbons for example : filters; discs; bearings; tubes an sheaths; worked fade), ncks and tiles; Or Other moulds for the manufacture of small articles of delicate design (e.g., coins, medals, lead soldiers for collections). (2) Carbon fibres and articles of carbon fibres. Carbon fibres are common1 produced by carbonising organic polymers in filamentary forms. The products are used, or example, for reinforcement. B (3) Articles made of peat (for example, sheets, c linder shells, pots for raising plants). Textile articles of peat fibre are, however, excluded 6ection XI). (4) Unfired bricks made of dolomite agglomerated with tar. (5) Bricks and other shapes (in particular magnesite or c h r o m e - m a y products), chemically bonded but not yet fired. These articles are fired durin the lrst heattng of the furnace in which they are installed. Similar products presented a er firing are excluded (heading 69.02 or 69.03). W (6) Unfired silica or alumina vats (e.g., as used for melting glass). (7) Touchstones for testing precious metal, these may be of natural stone (e.g., lydite, a hard, fine-grained dark stone resistant to acids). (8) Pavin blocks and slabs obtained by moulding fbsed slag without a binder, but excluding those aving the character of heat-insulating goods of heading 68.06. R. (9) Filter tubes of finely crushed and agglomerated quartz or flint. (10) Blocks, slabs, sheets and other articles of fused basalt; these are used, because of their great resistance to wear, as linings for pipes, belt-conveyors, chutes for coke, coal, ores, gravel, stone, etc. The heading also excludes : (a) Blocks, plates and similar semi-manufacturesof artificial graphite or of" other carbon ", mainly used for cutting into electrical brushes (heading 38.01) (see corresponding Explanatory Note). (b) Refractory goods, fired as ceramics, with a basis of carbonaceous substances (graphite, coke, etc.) and coal tar pitch or clay (heading 69.02 or 69.03, as the case may be). (c) Carbons, brushes, electrodes and other parts or articles for electrical uses (heading 85.45).