Barium sulfate is reduced to barium sulfide by carbon. The accidental discovery of this conversion many centuries ago led to the discovery of the first synthetic phosphor (Hollman and Wiberg, 2001). The sulfide, unlike the sulfate, is water soluble. Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for barium is shown below.

The Barium sulfate is a white crystalline solid that is insoluble in water. It is also known as Artificial barite which is an inorganic compound with the formula BaSO₄. Barium sulfate belongs to the product categories of Industrial/Fine Chemicals; Inorganics. With the CAS registry number 7727-43-7, its IUPAC name is barium(2+) sulfate. The white opaque appearance and its high density are exploited in its main applications. Additionally, its classification codes are Contrast Media; Diagnostic aid [radiopaque medium]; Drug / Therapeutic Agent; Mutation Data; Tumor Data. Due to its insolubility, Barium sulfate is nontoxic, although soluble salts of barium are moderately toxic to humans. The most common means of inadvertent barium poisoning arises from the consumption of soluble barium salts mislabeled as BaSO₄. 

Physical properties about Barium sulfate are: (1)ACD/LogP: -1.031; (2)ACD/LogD (pH 5.5): -5.53; (3)ACD/LogD (pH 7.4): -5.53; (4)ACD/BCF (pH 5.5): 1.00; (5)ACD/BCF (pH 7.4): 1.00; (6)#H bond acceptors: 4; (7)#H bond donors: 2; (8)Enthalpy of Vaporization: 62.94 kJ/mol; (9)Boiling Point: 330 °C at 760 mmHg; (10)Vapour Pressure: 3.35E-05 mmHg at 25°C

Preparation of Barium sulfate: Barium sulfate can be prepared by barium sulfide. It is soluble in water and readily converted to the oxide, carbonate, and halides. To produce highly pure barium sulfate, the sulfide or chloride is treated with sulfuric acid or sulfate salts:

BaS + H₂SO₄ → BaSO₄ + H₂S

Barium sulfate can also be prepared by purificatory barium chloride and refined sodium sulfate. After washing, leaching, drying, crushing, screening, testing, you can gain barium sulfate product.

BaCl₂ + Na₂SO₄ → BaSO₄ +2 NaCl

Uses of Barium sulfate: (1)As a mostly purified mineral, about 80% of the world's Barium sulfate production is consumed as a component of oil well drilling fluid. This substance increases the density of the fluid; (2)Barium sulfate can be used as radiocontrast agent. It is indicated for use as a contrast medium in x-ray diagnosis of the gastrointestinal tract. It is most often used in imaging of the GI tract during what is colloquially known as a 'barium meal'. (3)The majority of synthetic barium sulfate is used as a component of white pigment for paints. (4)Barium sulfate is a low surface area material used as a support for selectively hydrogenating functional groups sensitive to overreduction. (5)As barium compounds emit a green light when burned, barium salts are often used in green pyrotechnic formulas, but the nitrate and chlorate salts are more common. Barium sulfate is commonly used as a component of "strobe" pyrotechnic compositions.

When you are using Barium sulfate, please be cautious about it as the following:
This chemical may cause damage to health. It is harmful by inhalation, in contact with skin and if swallowed. It is irritating to eyes, respiratory system and skin. In case of contact with eyes, you should rinse immediately with plenty of water and seek medical advice. Whenever you will contact it, please wear suitable protective clothing. Finally, you must avoid contacting it with skin and eyes.

You can still convert the following datas into molecular structure:
(1)Canonical SMILES: [O-]S(=O)(=O)[O-].[Ba+2]
(2)InChI: InChI=1S/Ba.H2O4S/c;1-5(2,3)4/h;(H2,1,2,3,4)/q+2;/p-2
(3)InChIKey: TZCXTZWJZNENPQ-UHFFFAOYSA-L

The toxicity data about Barium sulfate is as follows: