The characteristics of Imogolite are:

[a] They are found in Andisol

[b] They have low bulk density and high plasticity

[c] They have a high potassium fixation capacity

[d] They are para-crystalline in nature

Choose the correct answer from the options given below:

Correct option is D

Correct option: (d) — (a) and (d) only
Explanation of correct statements:
· (a) Found in Andisols — TRUE
· Imogolite is a short-range order alumino-silicate mineral.
· Commonly occurs in volcanic ash soils (Andisols).
· (d) Para-crystalline in nature — TRUE
· Imogolite lacks long-range crystal order.
· Classified as para-crystalline / poorly crystalline.
❌ Why other statements are incorrect
· (b) Low bulk density and high plasticity
· While Andisols have low bulk density, imogolite itself does not show high plasticity.
· (c) High potassium fixation capacity
· K fixation is characteristic of 2:1 clay minerals (illite, vermiculite).
· Imogolite has very low K fixation capacity.
�� Key Points
· Imogolite:
· Short-range order mineral
· Found in Andisols
· Para-crystalline structure
· Low K fixation
· Important in volcanic ash soil chemistry.