Indicator minerals include minerals that have crystallized directly from a kimberlitic magma (molten kimberlitic rock), or minerals that have been incorporated into the kimberlitic magma as it ascends to the earth's surface. Examples of indicator minerals are picroilmenite, titanium and magnesium rich chromite, chrome diopside, magnesium rich olivine, pyrope garnets (varieties which include Dawson and Stephen's G1, G2, G9, G10, G11, G12 and Gurney's G9and G10 garnets) and eclogitic garnets (varieties which include Dawson and Stephen's G3, G4, G5, and G6). For the purposes of the property descriptions and unless specified, references to G9 and G10 garnets will refer to Gurney's G9 and G10 pyrope garnets.

There are a limited variety of diamond indicator minerals from which information pertaining to the diamond bearing potential of the host kimberlite can be gained. These are typically indicator minerals that have been derived from diamond bearing peridotite and eclogite in the upper mantle. The most common examples of these would include sub-calcic, chromium rich G10 pyrope garnets (diagnostic of garnet harzburgite), in some instances G9 pyrope garnets (diagnostic of garnet lherzolite), chromium and magnesium rich chromite (referred to as diamond inclusion quality or "DIF" chromite and diagnostic of chromite or spinel harzburgite), diamond inclusion quality "DIF" eclogitic garnets and chemically distinct chrome diopside (diagnostic of diamond bearing eclogites). Other indicator minerals that have crystallized from a kimberlitic magma can provide information as to how well the diamonds in a given kimberlite have been preserved during their ascent to surface. For instance, the presence of low iron and high magnesium picroilmenites in a kimberlite is a positive indication that the oxidizing conditions of a kimberlitic magma were favourable for the preservation of diamonds during their ascent to surface in the kimberlitic magma.