timeless marble dining and coffee table

hello to all ....i could really use some help please ,need advice on my two beautiful solid marble tables,,,i have purchased them second hand from where i live in spain, and am told they are approx 15/20 years old ,both tables are very very heavy and took 4 men to lift,,,i,ll try and discribe them as well as possible, as would like to know a few things about them ,,,one the name of the colour,,,,,two the design name and time/age,,,,and also as i am looking to sell them the value or what i could realisticly be ttryin to sell them for,and where.....not much help needed hey,,,ok the big dining table is one piece top, 165cm x 100cm,,it has a very educated metal pull push system inside the table to aid the movement and two extending pieces from each end to form an oval,,, total length when opened in full  210cm,the marble top is 2.05cm  thick, and has fibre glass layer covering the underside ,stamped marmol italia sl....marmolux.it stands on one base which is shaped ,and has 8 sides but not the same length the two panels that run parallel to the length are longer . i,m sorry i really was,nt sure of the correct for this shape,,,as they are not the same in length,,,the colour on first look is black and white ,,,,but as you look closer or in certain light it has a verydark red deep through it and also a green clour in places.the coffee table is exactly the same in colouring it measures 120cm x 70cm...rectangular base measuring 60cm x 30cm,,,again very heavy has the fibreglass layer and the red marmol stamp. the table top is bevelled ,2.05cmm slope which edges the outline. and the depth of the top is the same 2.05cm, it has a sticker on the base ssayin marmollux de italia sl and the address c/islas canaries pol ind fuente del jarro,,,,also both tables are like super shining/ almost to mirror finish ,you can see your reflection in them.ive searched online and at the address on the ticket , and have found one they are selling today tht is very simular to mine,,only half the thickness, and smaller or with smaller base ....they truly are so beautiful, and just classic,,they would look ultra modern or be fitting in a vintage setting ....well i,ll be looking forward to anyone getting in contact with me that could help in anyway,,thankyou in advance,,i,ll be keeping my fingers crossed. regards michelle xxxxx