The sulphide ore among the given options is Zinc blende (option D).

Zinc blende, also known as sphalerite, is a mineral that consists of zinc sulfide (ZnS). It is the most important ore of zinc and is commonly found in deposits alongside other valuable minerals. Here is a detailed explanation of why zinc blende is the correct answer:

1. What is an ore?
- An ore is a naturally occurring rock or mineral from which a valuable substance, usually a metal, can be extracted profitably. Ores are typically mined and processed to extract the desired metal.

2. Understanding sulphide ores:
- Sulphide ores are those ores that contain sulfide minerals, which are compounds of sulfur and a metal. These ores are generally processed through various methods to extract the metal. The metal sulfides are usually dense and have a characteristic metallic luster.

3. Haematite (option A):
- Haematite is an iron oxide mineral (Fe2O3). It is not a sulphide ore but an oxide ore. Haematite is the most important ore of iron and is widely used in the production of iron and steel.

4. Bauxite (option B):
- Bauxite is an aluminum ore. It is not a sulphide ore but an oxide ore. Bauxite is the primary source of aluminum and is used in the production of aluminum metal.

5. Rock salt (option C):
- Rock salt, also known as halite, is a mineral composed mainly of sodium chloride (NaCl). It is not a sulphide ore but a halide mineral. Rock salt is commonly used as a seasoning and for various industrial applications.

6. Zinc blende (option D):
- Zinc blende, or sphalerite, is a sulphide ore of zinc (ZnS). It is the main ore mineral for zinc and is typically found in association with other sulfide minerals such as galena (lead sulfide). Zinc is widely used in various industries, including construction, automotive, and electronics.

In summary, among the given options, only zinc blende (sphalerite) is a sulphide ore. Haematite is an oxide ore, bauxite is also an oxide ore, and rock salt is a halide mineral.