Information on the composition of magnesite

£/A/\ -M /K lA j Q<XAj GLCcuo . 'O / t * s Q U / U U i s - v Z l Smsm&C' 1 ^ r cyy^JUMM^L* t * "i ^i £ 4 4 A W V V ' ) 2 ^6VUr&£rCu aasZ-*u L j ^? OsUsK. f<3sVl& LCi^vH, /Jr/ TO J 1 U 1 4 A C 1A_> H^WA. ^Li/v HAGUESITE Magnesite is pure carbonate of magnesia , that is, HAG11SIA, 47.6 and carbonic acid, 52.4 per cent. It usually occurs missive or fibrous, but sometimes granular, and its fine, rhombohasdral crystals are well known. Like Dolomire, its prevailing tint is yellow, or light brown, but^ when v«jry pure, it is as white as snow.. It is usually associated itn serpentine rocks. 'In the kiln i?fas Lightly refractory and behaves" very much in the same way as lime, forming fusible compounds with silica and silicates. For the highest grades of basis brick, it is at this moment largely exploited in the few localities where it occurs ia^ paying quantities, A few years since, investigations to determine ohe best basis refractory material w^as actively prosecuted in Germany and magnesia pre-heated at the highest white heat, was awarded with palm. Magnesite when calcined, yields magnesia, which, however, still contains the impurities that might have been present in the raw material. An average percentage composition of the magnesite of commerce 8h0V78 i1: to °cataln magnesia .45, canonic aeid, .50, lime 1.5, protnyiaa. of iron, 1.6, the.remainder nexng as SSd pro t oxide of magnesia. The presence pf silica in magnesite is an objection because it is liable to have a fluxing effect at high temperature Magnesite has been found in paying quantities in California, Syria and recently in Greece, in lube a, in the last mentioned country, the minerals occur in lodes when nea^Krimasi, ar£ worked oil the l ev*i« 50 to 40 feet from the top, and dipping at an angle o£ about 70. The general average of the lode gives1, 88 per cent of carbonate of magnesia, and the substance is peculiarly suitable for the manufao of basis bricks, A novelty with the raw material is that the prepara are sold either by guaranteed degree or degrees of^analysis, the o ^eing 85 per cetit pf pure maghesiaT^fhfl st'^Sd' 1st ter|often giyes^ as ^ much as 98.7 per cent. In inferior grades the principal increase ia in the proportion of silica.