What is the Difference Between Calcium Oxalate Monohydrate and Calcium Oxalate Dihydrate

The key difference between calcium oxalate monohydrate and calcium oxalate dihydrate is that calcium oxalate monohydrate crystals have a smooth surface, whereas calcium oxalate dihydrate crystals have jagged edges.

Calcium oxalate can be described as a salt of calcium with oxalate anion. This substance forms as hydrates having the chemical formula CaC2O4.nH2O. The “n” in this formula can vary from 1 to 3. If it is zero, then it can be named as the anhydrous calcium oxalate. However, both anhydrous and hydrated forms are colorless or white.

1. Overview and Key Difference
2. What is Calcium Oxalate Monohydrate
3. What is Calcium Oxalate Dihydrate
4. Calcium Oxalate Monohydrate vs Calcium Oxalate Dihydrate in Tabular Form
5. Summary – Calcium Oxalate Monohydrate vs Calcium Oxalate Dihydrate

What is Calcium Oxalate Monohydrate?

Calcium oxalate monohydrate is a salt of calcium and oxalate anion having one water molecule forming the hydrate form. Therefore, the value of “n” in the CaC2O4.nH2O general formula is 1. It has a molar mass of 146.11 g/mol. Calcium oxalate monohydrate is a naturally occurring compound in the form of the mineral whewellite. This forms envelope-shaped crystals that are known as raphides. The monohydrate form of calcium oxalate is the most abundant form of this salt compound.

This substance occurs in the solid state at room temperature and pressure conditions. Sometimes, we can find it as a white hygroscopic powder or lumps that are odorless. The parent compound for calcium oxalate monohydrate is oxalic acid. This substance is used as the active ingredient in 7 major products, including Calcarea oxalica and cal-5-revive. Moreover, it is useful in the manufacture of ceramic glazes, for the separation of rare-earth metals, and for the analysis of calcium. Moreover, calcium oxalate monohydrate can cause irritation, and it can be harmful for ingestion and skin absorption.

Further, the shape of the calcium oxalate monohydrate crystals can vary. The most common shapes include dumbells, spindles, ovals, or picket fences. The picket fences can be observed due to ethylene glycol poisoning.

When considering the health condition of “kidney stones,” the most common type is calcium oxalate monohydrate stones. These stones form due to crystal retention in the renal tubules. Typically, these crystals tend to adhere to kidney cells and aggregate to form kidney stones.

What is Calcium Oxalate Dihydrate?

Calcium oxalate dihydrate is a salt of calcium and oxalate anion having two water molecules, forming the hydrated form. It is a rare hydrate of calcium oxalate. Its chemical formula can be given as CaC2O4.2H2O. It naturally occurs in the form of the mineral weddellite. Typically, calcium oxalate dihydrate crystals are octahedral. A large portion of crystals in urine sediments displays this morphology. Moreover, calcium oxalate dihydrate can grow at any pH, and it occurs naturally in normal urine.

Eating food with high protein contents can cause the formation of calcium oxalate dehydrate stones in the kidneys. Moreover, eating a diet high in sodium salt also can cause the buildup of calcium in the urine. Typically, the calcium oxalate dihydrate crystals have jagged edges, unlike in their monohydrate crystal form.

What is the Difference Between Calcium Oxalate Monohydrate and Calcium Oxalate Dihydrate?

Calcium oxalate monohydrate is a salt of calcium and oxalate anion having one water molecule forming the hydrate form, while calcium oxalate dihydrate is a salt of calcium and oxalate anion having two water molecules forming the hydrated form. The key difference between calcium oxalate monohydrate and calcium oxalate dihydrate is that calcium oxalate monohydrate crystals have a smooth surface, whereas calcium oxalate dihydrate crystals have jagged edges.

The following table summarizes the difference between calcium oxalate monohydrate and calcium oxalate dihydrate.

Summary – Calcium Oxalate Monohydrate vs Calcium Oxalate Dihydrate

Studying calcium oxalate is an important topic because it is the main component in kidney stones. There are two types of calcium oxalate as the monohydrate form and the dehydrated form. The key difference between calcium oxalate monohydrate and calcium oxalate dihydrate is that calcium oxalate monohydrate crystals have a smooth surface, whereas calcium oxalate dihydrate crystals have jagged edges.

Reference:

1. Zhao, Yao-Wang, et al. “Comparison of the Adhesion of Calcium Oxalate Monohydrate to HK-2 Cell: IJN.” International Journal of Nanomedicine, Dove Press.
2.“Calcium Oxalate Monohydrate.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.