Peetambar & Kautubh Mani
The lord, appearing on the shoulder of Garuda, seemed like a cloud resting on the summit of the mountain known as Meru. The body of the lord was covered by attractive yellow garments (peetambar), and His neck was decorated with the jewel known as Kaustubha-mani. The bodily effulgence of the Lord dissipated all the darkness of the universe.” (Shrimad Bhagavatam, 4.30.5)
Thus Yellow garments mean Peetambar(peet-yellow, Ambar-clothes)
Kaustubh was the 4th gem which came from Sagar Manthana. And devas offered it to Shree Hari.
Srī Vatsā cinhā
Srī Vatsā cinhā is the mark on right side of chest of Shri Hari. Where devi Laxmi resides. Every vigraha of Vishnu has it. For more read Here

The cinhā is marked, as you see.
could name all the important ornaments of Lord Vishnu and his consorts on his chest.
Every Vigraha has different Abharan and Asbhushans. Will explain abt, Balaji and Vitthal here.
Venkateshwara, Tirumala

One ornament missing here is Vajra Kavach, which is bedecked on his chest.
The Mukhut on his head is known as Vajra kirita.
Vaijanthi mala is his favourite garland thus adorned with it.
Surya Katari is the sword of Venkateshwara.
Makar Kundala (Makar shaped) are one type of earrings mentioned for male deities in Agams.
After the vigraha is done with alankaram, Laxmi and Padmavati are adorned on the chest of Venkateshwara. Thus giving the true name to the lord, Shree Nivas.(The place where Laxmi resides)

Devi Laxmi on left side and Padmavati on right side of the chest.
Vitthal, Pandharpur

The ear rings here are Matsyakundal(fish shaped).
Between the feets of Vitthal is a stick with Bells(ghunghru).
Mukhut which looks like a hat, but is called Shivling.
A 3 roped waist band called Mekhala.
Some common features -
2 kadas(Bajuband) on arms, Kaustubh Mani on chest, Srī Vatsā Cinhā on right side of chest, Lotus in right hand, and conch in left, and the lord is standing on Brick (in marathi brick is called as Vith, thus the name Vitthal)
Hope rest is vivid here.
कालिकार्पणमस्तु ।🌺