What is the difference between banded Crustiform and Colloform?

Crustiform is a fine banding of microcrystalline quartz and comb quartz that developed from both wall. The colloform occur as concentric curve and under microscopic show fine-grained and coarse- grained quartz overgrowth texture. The banded texture can observed by the apparent of hand specimens.

What is Colloform texture?

Said of the rounded, finely banded kidneylike mineral texture formed by ultra-fine-grained rhythmic precipitation once thought to denote deposition of colloids.

What is Colloform?

Definition of colloform : having the form or shape of a colloidal deposit : botryoidal, mammillary, and usually internally banded concentrically.

What is Crustiform banding?

Crustiform banding. When minerals grow within a vein, they often grow inwards from the vein wall. Several layers of different types of minerals, representing different pulses of often aligned symmetrically away from the center of the vein. Comb structure.

What are vein textures?

Veins are dilated fractures filled with oriented crystal fibers or non-oriented mineral deposits (typically quartz, calcite or carbonates). Veins occur in rocks of all types and metamorphic grades with thickness from less than a millimeter to several meters.

How do you identify goethite?

Goethite typically has a yellow or brown color while hematite is typically red. Goethite is an iron oxyhydroxide. The formation of goethite is marked by the oxidation state change of Fe2+ (ferrous) to Fe3+ (ferric) iron, which allows for goethite to exist at the earth’s surface.

What is meant by ore grade?

The grade of ore refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of sufficiently high grade to be worth mining, and is therefore considered an ore.

What is a tabular ore body?

the general name for an accumulation of ore in any shape. The sheet, the most common shape in which sedimentary deposits occur, is a tabular body separated from other rocks by bedding planes. A distinction is made between simple sheets and complex sheets, which have rock interlayers.

What is a quartz vein?

Vein Quartz. Quartz is often found in veins that cut through rocks. Although the term “vein” suggests this, the veins of quartz and other minerals are usually not thin tubes, but rather thin sheets. The simplest type of a quartz vein is the filling of an already present crack in rocks.

What does goethite look like?

Goethite is a common mineral. It can be brownish yellow, reddish brown, or dark brown in color, depending on the size of the crystal in the specimen—small crystals appear lighter, and larger ones darker. Goethite is an iron oxide hydroxide, although manganese can substitute for up to 5 percent of the iron.

What type of rock is goethite?

It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient times for its use as a pigment (brown ochre)….