Hongyan stone cannot be evaluated. Red vinegar is good. Hongyan is a geological phenomenon, also known as Hongyan. Rock is rock, which is formed by crustal movement and erosion and corrosion. Hongyan is a kind of red rock containing a lot of iron oxide (Fe2O3). After crustal movement, erosion and dissolution, beautiful geological wonders have been formed. Red vinegar is a kind of vinegar. It is rich in calcium ions and amino acids, which can increase the strength of bones, whiten skin and eliminate pigmentation on the face. It has adjuvant therapeutic effect on freckles and chloasma, and the acidic substance of red vinegar can soften blood vessels, which has certain preventive effect on cardiovascular and cerebrovascular diseases such as arteriosclerosis.