Diamonds from modern deposits of Siberian Platform. 2. Lena-Anabar Subpro-vince
Diamonds from modern placers of diamondiferous regions of Lena-Anabar subprovince are comparatively uniform and, in whole, are close to crystals from more ancient secondary collectors edging placer occurrences. The low content of diamonds of kimberlite type original source is characteristic of the described placers and diamond occurrences. Increased mechanical wear, growing from marginal parts of Anabar anteclise towards Anabar crystalline massif is general for modern placers of the region. For the Quaternary deposits of the Abelyakh diamondiferous region high content of gray, overfilled by inclusions of graphite, rhombohedra of variety V (according to Y.L. Orlov’s classification) and complicated dodecahedra of variety VII, not found in kimberlite diatremes of the region, is typical. Coarseness and quantity of diamonds of these varieties decrease from west to east of the region. The presence of relatively fresh diamonds of the Nizhne-Lensky type (without mechanical wear and poorly ferruginizated stones) is also a distinctive indication of modern placers of the region. The typomorphic indications are successfully used for the zoning of this territory in the process of carried out geologic-prospecting works.